Thanks in advance for going through all my writing. 
 
Okay I am quite new to this cooling process but have read a bit about it from forums on here and a bit through Googling.
 
The setup I want to run is basically air. I do not plan on going on the super high end of performance/gaming so I do not want liquid cooling nor do I think I will need it.
 
My current computer setup:
 
Cooler Master HAF-912 Mid Tower * All stock fans etc. *
Cooler Master Hyper 212 Plus+
Gigabyte GA-Z68MX-UD2H-B3 
Intel Core i5 - 2400 LGA 1155  * used the Gigabyte EasyTune to up it to 3.4GHz *
Cooler Master Extreme Power Supply 700W   
Corsair Vengeance (4) 4GB DDR3
(2) EVGA 460 1GB GTX SC in SLI  
(3) 1 TB HDD 
 
Problem is that with my current motherboard I only have 2 places to power the fans.  So obviously I need one for the CPU so the Hyper 212 Plus+ does that.  Then I got the other slot filled by the back fan on my HAF-912 tower.
 
So I have the front intake fan not being powered right now.  
 
When idling my CPU hovers around 25-35C.  GPU 1 Around 40-50C and GPU 2 Around 35-45C. Fans are on auto from the EVGA Precision tool.  ( Idles around GPU Fan Speed: 30% )
 
When I game my GPU temps hit from 70-80C. Which isn't too bad but the fan is around GPU Fan Speed: 50-60% which starts to get a bit loud. 
 
My CPU temps when I'm gaming never hits above 60C.  
 
I would like to improve airflow which I assume will lower the temperatures all across the board for my CPU and my GPUs. Thus lower temperatures will let the fans run at lower speeds which would lead to less fan noise.
 
So I would need to add extra fans and get the one fan that is not being used right now to be powered.  The problem I run into is that now I have a Cooler Master Extreme Power Plus 700W PSU.  Due to SLI and the (2) 460 GTX cards requiring (2) 6 pins I used the (2) pins from my PSU into the 1st GPU and had to use molex connector/adapters to power the 2nd GPU.  Now I have no more power lines and seems like my PSU is tapped out.
 
Is there something I am doing wrong with my power setup or do I really need to upgrade to another PSU?  I heard that powering too many fans from the motherboard is bad and there are pins to molex adapters you can use.  However, I am out of power lines to even connect any additional fans.  
 
What would be the best thing to do here?
 
Front Side of my HAF-912  * As you can see the front fan on the bottom is not working because it is not powered *

 
Left Side of my HAF-912 Tower. * There is no side fan/vent on there *

 
Top of my HAF-912 * Also no exhaust fan or radiator *

 
Now the backside of my HAF-912.  * That stock fan is working on the top right *

 
Overall layout of the inside.  * At top is obvious that same stock fan ( which is powered ) from the previous picture *  The Hyper 212 Plus+ fan also working.  * Which fills the 2/2 motherboard spots for fan power *.  Then I got my 4 ram cards.  Below is my two evga 460 gtx sc cards in sli.  I could not space my cards any more further apart. That was the furthest apart I could space them on this motherboard. Then I got my 3 HDDs on the bottom right I also spaced them apart to not let them run too hot.

 
Here is a picture of my cards and the power a tad closer. As you can see the main (2) 6 pin rails are plugged into my top card while I had to use molex adapters to power my 2nd card.  The PSU is a 700W Cooler Master Extreme Power Plus.

 
So I really have no more lines to get my power from. I can't even run an extra HDD even if I wanted to.
 
I am a tad messy with my lines and will get that sorted very soon.  So what can I do?  Is my only choice to upgrade to another power supply that has more rails to power my GPU and use the extra lines to power any other fans?
 
What my thought was to see if any other power supplies like an 800-900 power supply has more rails to directly power my 2 graphics cards and then use the extra molex and buy adapters from the 3/4 pin fan connectors to molex then add those fans somewhere.  
 
I see that the method for air cooling you want Positive Air Pressure thus I would want more intake than exhaust. So currently I have 1 exhaust and no intake which creates Negative Air Pressure if I understood it correctly.  So I would first want to have that bottom intake fan from the front side of my tower to be powered.
 
Only problem is that the fan's power line is too short to reach the slot on the motherboard so I can't even power it that way even if I wanted to.  So in this case to create more intake I first of all I need to power that 1st bottom intake fan and perhaps add another intake fan below it?
 
If I wanted to do that what would I need to do? Is my thought of getting the new psu and getting the adapters to power the new fans correct?  
 
In general I don't expect to run a super machine but I want to keep it cool and quiet enough so it doesn't bother me or anyone else in my house.   
 
Sorry for the long post but I hope the information I provided helps you direct me in the right direction.
P.S. One last mini question. Would adding another fan to the Hyper 212 Plus+ help? or would that be bad?
 

A modular PSU would really help with that system, lol. 

You can just plug the fans into motherboard headers, and when you run out use the PSU molex chains and adapters if you need.  Those PSUs I recommended will have sufficient cables.
 
Modular PSU resistance doesn't impact performance much these days.  Even the best performing PSUs today are partially or mostly modular.  
 
The TX850 V2 is good, but you can get better for $100.  This is an amazing deal really, 910W is plenty for an overclocked GTX 580 SLI system.
 
http://www.newegg.com/Product/Product.aspx?Item=N82E16817703022&Tpk=pc%20power%20%26%20cooling%20910w

HotRodPolk

Make sure you get Corsair Gaming as they are proven to be the most reliable psu series out there, outside of the Professional Gold series.
Corsair Gaming series 800:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139025

 
Not even close.  That's just pure Corsair fanboyism right there.  For the price of the Gaming series, you're better off with a TX V2 anyway.  However that PC P&C 910W unit I listed is much better, as reviews like this one show.
 
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=157
 
Less money for a PSU that performs better and has more room for more powerful hardware?  I'll take that.  You did mention a fan controller which is a fine idea.  Lamptron is the best, in my opinion.  I don't know of any other with such high wattage channels.  I use the FC-2 which has 6x 45W channels (3.75A).

boredgunner

HotRodPolk

Make sure you get Corsair Gaming as they are proven to be the most reliable psu series out there, outside of the Professional Gold series.
Corsair Gaming series 800:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139025

Not even close.  That's just pure Corsair fanboyism right there.  For the price of the Gaming series, you're better off with a TX V2 anyway.  However that PC P&C 910W unit I listed is much better, as reviews like this one show.

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=157

Less money for a PSU that performs better and has more room for more powerful hardware?  I'll take that.  You did mention a fan controller which is a fine idea.  Lamptron is the best, in my opinion.  I don't know of any other with such high wattage channels.  I use the FC-2 which has 6x 45W channels (3.75A).

You are correct, it is fanboyism. I trust Corsair, and only recommend them. Until another brand proves to be as reliable, that won't change...

HotRodPolk

boredgunner

HotRodPolk

Make sure you get Corsair Gaming as they are proven to be the most reliable psu series out there, outside of the Professional Gold series.
Corsair Gaming series 800:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139025

Not even close.  That's just pure Corsair fanboyism right there.  For the price of the Gaming series, you're better off with a TX V2 anyway.  However that PC P&C 910W unit I listed is much better, as reviews like this one show.

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=157

Less money for a PSU that performs better and has more room for more powerful hardware?  I'll take that.  You did mention a fan controller which is a fine idea.  Lamptron is the best, in my opinion.  I don't know of any other with such high wattage channels.  I use the FC-2 which has 6x 45W channels (3.75A).

You are correct, it is fanboyism. I trust Corsair, and only recommend them. Until another brand proves to be as reliable, that won't change...

 
lol, other brands have been "reliable" since before Corsair entered the PSU market (looks at PC Power & Cooling, Seasonic, Zippy, etc.)  If you mean Corsair support, then that's a different story.

Yate Loon medium speeds are fine for case fans, you don't need anything too intense.  Yate Loon high speeds outperform the stock fans on your CPU.  The best Yate Loons come from Petrastechshop and Sidewindercomputers - larger coils, larger/stronger magnets, and better capacitors which make them live longer and stay within the RPM range better.  However there is less of a guarantee of getting these higher quality Yates these days.
 
So I say get one or two Yate Loon high speed fans for the CPU cooler.  The static pressure is around 4 mmH2O judging by performance (never seen a definite number).  For radiators/heat sinks they outperform any Cooler Master fan (I think it was Sleepee who confirmed this), and they also outperform Scythe Ultra Kaze fans (loads of crap) as well as pretty much any other fan in the price range.  If you go with one, put it on the pull side of your CPU cooler (closest to rear fan), and remove the rear case fan.
 
Yate Loon medium speeds will do fine for the case side panel and front.  

Simba123

where are you shopping at?

Definitely push pull on the hyper 212+  work out whichever fan has the higher CFM and put it on the PULL side. 
I'd leave the rear fan in, or upgrade it to a higher CFM rather than take it out.

By the looks of it you need to buy 3 or 4 fans
1 or 2x120mm for the top(Exhaust)
1x120 mm for the left side (intake)
1x120 mm as a second fan for the 212+

You don't need to spend massive amounts of money on these.
2 of these one on your side panel, 1 on your Hyper 212+ 7.95ea
1 or 2 of these for the top panel 17.99ea
you need the more expensive ones on top due to the horizontal orientation.  Rifle/SSO bearing fans are much better than sleeve fans for that orientation. Unfortunately, they are also more expensive.

my 2c anyway

 
 
Slipstreams are worthless.  I had two of them die on me within months, probably due to the motor being designed to spin 80mm fans and not 120mm.  Performance is worse than the competition, especially with static pressure but that hardly matters on a case.  Yate Loon medium speeds are cheaper and much better.  They undervolt better (my Slipstreams clicked when undervolted, my Yates don't), they live much longer and there should be less deviation in the RPM.  $6 a piece, 70 CFM @ 33 DBA.  Go for one on the side panel (intake), and an extra on the front (intake).  
 
http://www.petrastechshop.com/12yalod1cafa1.html
 
One of those would be good for the Hyper 212+, or the high speed version.
 
http://www.petrastechshop.com/12yalod1cafa2.html
 
I agree about not getting a sleeve bearing fan for the top.  In that position they'll just be louder, struggle to move air, and die quicker.  Those Noctuas are great, although if you want to save some cash you can look for Scythe GentleTyphoon AP-14s.  They perform about the same, and use dual ball bearings (much quieter than one ball bearing).  Good luck finding them though.
 
About bearings - for horizontal positions you'll be much better off ball bearings (one or two), or certain fluid bearing designs.  Silverstone's are good (in fact their modified sleeve bearing on the AP181 works well too, from what I've read), Sony's are good, Noctua's are supposed to be great (and magnetized), and Panaflo's are great.  I'm sure there are others too.  Fluid bearing design comes from sleeve bearings so some of them have some of the same issues as sleeve bearings.

The HAF 912 comes with one 120mm intake fan.  $20 for 4 is great, so you can pick that up.  One for the front, one for the side, one for the cooler, and one for the top.

xskballerx

Ah the name didn't appear when I posted last night.  

I was looking at 4-5 of these.

Scythe Kama Flow2 SP1225FDB12H

would these work also?  I'm looking for a fan that will be pretty quiet but gives me solid performance and will last a decent amount of time.

I'm planning ahead because I maybe out of the U.S. in a few months and might be harder to order when I move to my new place.

No those fans are supposed to be junk. Where are you shopping at?

HotRodPolk

xskballerx

Ah the name didn't appear when I posted last night.  

I was looking at 4-5 of these.

Scythe Kama Flow2 SP1225FDB12H

would these work also?  I'm looking for a fan that will be pretty quiet but gives me solid performance and will last a decent amount of time.

I'm planning ahead because I maybe out of the U.S. in a few months and might be harder to order when I move to my new place.

No those fans are supposed to be junk. Where are you shopping at?

 
Are they really?  They appear to use the same Sony fluid dynamic bearing as S-Flex and Thermalright FDB fans.  Not sure on the overall build quality of Kama Flow 2 but S-Flex and TR FDB fans are actually very good.  

xskballerx

So I could use 5 of the Scythe S-FLEX SFF21F right?

1 for the intake on my side. 2 for the intake on the front.
1 on the Hyper 212+ and the last perhaps for an exhaust on the top and back.

 
If you put one on the Hyper 212+, put it on the front/push side since the stock fan has higher pressure and CFM than that S-Flex.  Also don't bother with a rear case fan unless it's more powerful than the CPU fans, otherwise it might actually slow down airflow and increase temps a tiny bit (I've experienced this, and many others have too).  But those are a good choice.  I have two of Thermalright's versions (same fan but mine are 2000 RPM), and while the FDB proves not to be as quiet as Panaflo's hydro wave bearing, it's still great in performance and has never died throughout the years.

Fans will help but may i also add CABLE MANAGEMENT!!!! This will help alot

Good luck.  I'm sure it will be possible to achieve good cable management, but not easy since your case is on the small side and you're dealing with a non-modular 910W power supply.  I've seen people make rigs like this look nice.  Takes time.  

Hm... Looks like sidewindercomputers is out for awhile.  Been 4 days and no update. They refunded the charge on my card but gave me no notice...
 
Might be looking for a different fan then I guess.