DQ965GF Compatibility worries...

Ok, Now I bought this sweet new Custom/whitebox PC from eBay and the motherboard is DQ965GF and I desperately want to play the new and upcoming game APB which requires a GeForce something or other 7000 something or more. I'm not PC illiterate or anything though when it comes to the innards of a PC I'm almost completely lost. Could anyone tell me what graphic cards are compatible with this mother board that's as powerful as the GeForce 7600 gt I think it is? Also I'm getting a intel core 2 duo too since I have a something 775 socket lol, The question relative to that is what amount of hard drive space am I going to need for it since I heard that makes a considerable difference and also should I actually just go and get a quad? I wanna run any thing at it's max settings and sit in awe of the awesomeness. lol I sound a little deranged I know but please help me someone.lol Upgrading a PC is outrageously expensive and I dont wanna get the wrong stuff.

I'd appreciate any kinda help I could get. Thank yez!