I'm planning on upgrading my 1080p Sony monitor to an LG 4k. My pc isn't powerful enough to max out games at 4k so I wanted to know if I play at 1080p, will it still look good on that 4k? If it looks just as good as my current, then I would be happy......

No monitor looks good when the resolution is turned down... Not that I've seen anyway...

jiannu - I think your pc should be good enough to play games at 4k, you will just not be able to turn up the eye candy.  You will have to play with the settings to see what looks best between the different resolutions and settings.

You will be able to play most games fine in 4k if you don't care about hitting 60fps. If you are ok with 30 ~ 50 you will be all right.

Anyway.. as I am waiting my Titan X, I am playing 1080p (MKX and GTAV) in a 4k screen. However it's a TV not a monitor. It might be a long shot, but here how it is with a TV (maybe 4k monitors are the same way, I donno):
I am playing in a 65" at 1080p.. but the TV has an upscale engine, so instead of my computer doing the stretching to make the pixels 4 times bigger to fill up the screen, my TV will handle it. What this upscale engine does, is scatter all the pixels evenly across the screen, and then "guess" the gaps to fill up the missing pixels. Of course it doesn't look as good as running in native 4k, but it looks well damn better than it does if I let my GPU stretch the image 4 times.

Then again, this is a Smart TV thing and how it apply filters to make 1080p content looks better than it would in a 1920x1080 screen. You might want to research and see if monitors has something like that as well or consider getting a TV instead.
Good luck

jiannu
Vidal;
That's what I was considering was a smart 4k tv. Which do u recommend? I'm planning on getting lg 8000 series or might wait for Samsung 8550 series.

It's difficult to recommend as I only have 1.. lol.
The one I am talking about is the Samsung HU9000 curved.

The thing is, Samsung have just released their 2015 line of TV.. which means they pretty much removed from the market all 2014 models, including the HU9000 and all other HU series (7000, 8000) etc.. and replace with the new JS9000 (JS8000, JS7000) etc...

Those are full retail price now and really expansive. If you look hard enough you might still find 2014 models very cheap now somewhere, but they are getting harder to find everyday.

Just for comparison, if you find the HU9000 (2014) in some online store or whatever, it will be cheaper than a JS7500 (2015) even though the HU9000 is much better and more advanced than the JS7500... Series 9 x Series 7 of course.
So I'd hurry up if I were you and try to get some cheap 2014 TV before they are gone. Samsung is not replacing stock... so they are out there only till stocks last.. After that you gonna pay more for a lower TV or pay twice as much for one of the same series.

Vidal;
I too have a Samsung for my tv a 65uhd8550 and absolutely love it! Got a really good deal on it. I'm not sold on the curved idea. My 8550 has all the same features of the 9000 minus the price tag.
Stalinx20;
I heard it's not worth the 3rd 970 for tri sli. I would in the future upgrade to a better card like a Titan x when it's affordable.

jiannu
Vidal;
I too have a Samsung for my tv a 65uhd8550 and absolutely love it! Got a really good deal on it. I'm not sold on the curved idea. My 8550 has all the same features of the 9000 minus the price tag.
Stalinx20;
I heard it's not worth the 3rd 970 for tri sli. I would in the future upgrade to a better card like a Titan x when it's affordable.

I heard completely different about 3 970's. Don't let people that had a bad experience with SLI 970's discourage you because they were using the cards the wrong way for the wrong reason, from going that route IF you did infact consider going going 3 970's. Everyone that did have 3 970 setup had nothing but good things to say so long as they did have the proper hardware to run 3 way setup.
 
Usually it's the people that have never had the experience of going 3way/4way SLI are the ones that are going to put 3 way and 4 way SLI down, because they're jelly as &#$@. lol