Need help with some build stuff

hey guys, i'm fairly new to the computer gaming scene and just bought my first gaming pc about 2 months ago. Anyway, i was needing help knowing what i need to buy and if my setup could support dual gpus because right now thats my system's bottleneck. Here are my current specs:

 

(im looking at getting another amd 7870) I know im going to need better cooling for my gpu(s) and will most likely need a better psu (will 900 watt work?). I also do not know if i can run dual gpus on this motherboard and was hoping someone with better knowledge could help me out. If you have any ideas, or suggestions it would be greatly apreciated. Also i would like to keep total cost for cooling the gpu and psu below 400 bucks if at all possible.

 

I'd get a better Mobo aka 990fx also get the same make and model 7870 and finally a 750 watt psu could take care of it

heres a rough list http://pcpartpicker.com/p/1gqSB