My comp forum of choice atm is HardForums.com.
There is a computer/video game section found here:
http://www.m3post.com/forums/forumdisplay.php?f=170
Back in January another user had a similar situation. This is a build I threw together really quick for them. While it is over budget for you, there are some pretty simple changes you could make that would drastically lower the price.
Links to components:
http://www.m3post.com/forums/showpos...0&postcount=21
This build is honestly maybe a little out of date now don't use it verbatim. A lot of newer components have come out since. Switch out the 580 for 560 Ti or AMD equiv. and instantly save a few hundred $$$, remove the Intel 320 SSD and save more. Get one of the new ivy bridge 3570k processors and save a bit more. It is possible to make a fantastic gaming machine for only $1300 or maybe less if you take your time getting the components.
If you would like, I'll throw an updated build up when I get time.