Well considering you can customize it, it's not really the 'model' you should worry about.
http://www.cyberpowerpc.com/saved/1DDJGU
That's what I configured for you, just under budget. No monitor, going to come with freebies in the mouse/keyboard dept. X-fired 6850's, 8gigs of ram, a Creative X-Fi soundcard and a 5.1 speaker system to go with. Standard 2500k(no overclock, you can do that yourself and its super easy), and you'll pretty much rock any game that comes out anytime soon without any trouble. The only thing that setup is lacking is the OS, which you'll need a 64 bit OS Windows 7. You can add that in there and play with the config a bit yourself, but with 2k to spend you have a lot of options. I would definitely look at benchmarks from Passmark and Anandtech to compare hardware to see where best to cut the price down if you want to.