My current monitor is old and is starting to go bad (dark colors are starting to fade out) and I'm looking to buy a new one over the 4th of July weekend as I hope to get a good deal on one.  My issue is, I know nothing of what I should be looking in a monitor.
 
So, if someone (or a few people) could give me an idea on what to look for when buying a new monitor that would be appreciated.
 
Thanks!

Setup is...
 
i5 4670k w/Corsair H100i
MSI Z97 Gaming 5
Corsair Vengeance 32GB
EVGA GeForce GTX 970 FTW+ ACX 2.0+ (I may go SLI if I can find this same card onsale this weekend as well)
Samsung Evo 500GB SSD & WD Black 1TB
Corsair HX1000w

Would like to stay under $400 or right around there is fine.
 
In the past I have always had a two monitor setup, this time around I'm thinking of just one nice monitor - maybe one of those curved ones?  
 
This will be used only for gaming (I play mostly MMORPGs or Civ 5 because I can't quit that game).  I have a really nice TV that I watch all my movies and stuff on, so wouldn't be using the monitor for that.

Aqualoon
Would like to stay under $400 or right around there is fine.
 
In the past I have always had a two monitor setup, this time around I'm thinking of just one nice monitor - maybe one of those curved ones?  
 
This will be used only for gaming (I play mostly MMORPGs or Civ 5 because I can't quit that game).  I have a really nice TV that I watch all my movies and stuff on, so wouldn't be using the monitor for that

Aqualoon
Would like to stay under $400 or right around there is fine.
 
In the past I have always had a two monitor setup, this time around I'm thinking of just one nice monitor - maybe one of those curved ones?  
 
This will be used only for gaming (I play mostly MMORPGs or Civ 5 because I can't quit that game).  I have a really nice TV that I watch all my movies and stuff on, so wouldn't be using the monitor for that.

There are curved monitors in that price range or close @ 60hz \ 4ms gtg. Google is your friend 120 hz is smooth but u pay. If you don't mind 60hz on WOW type games go for it I think you'll be happy

Sounds about right.  I doubt you will find a g-sync monitor that is 120hz - most gsync are 60hz or 144hz now-a-days.  But as everyone said - it'll cost but it's well worth it!

Aqualoon
Think my GPU would be able to handle an Acer XB280HK?

4K? Not really, your frame rates will tank. For your budget I'd take a look at these:

http://m.newegg.com/Produ...number=N82E16824009848

http://m.newegg.com/Produ...mnumber=9SIA6R43V59422

Aqualoon

mike406

Aqualoon
Think my GPU would be able to handle an Acer XB280HK?

4K? Not really, your frame rates will tank. For your budget I'd take a look at these:

http://m.newegg.com/Produ...number=N82E16824009848

http://m.newegg.com/Produ...mnumber=9SIA6R43V59422

Upgraded my GPU from what I posted previously to be able to handle the monitor.

I would take a look at 4K benchmarks with the Titan X and you'll need to decide if those FPS results are okay for you. They're much too low for my liking personally.

2k 144hz is the sweet spot for sure! I currently have a 2k and get 80 - 100fps with most games on ultra with my 1080 and i7 6700k. If you are going to stick with a single 970 I would stay at 1080p and get a 144hz refresh rate for it to look silky smooth. I ran a 970 with my 2k before getting my GTX 1080 and it struggled a bit.

fearpoint
970 is a 2k GPU. It's overkill for 1080p.

Not really...With all the eyecandy turned up on recent games it barely keeps 60 fps on 1080p.