Check my sig out, my rig is blasting through Battlefield 3 64 Multiplayer Matches with an overclocked HD 6670 from ASUS. Dust proof fan too! =D
But anyway, Intel is the way to go for gaming because of the nice boost you get. Are you planning on overclocking? If you are, SB, if not or don't want to go past 4.5 GHz, then IB should do the trick. I had someone put it together and it was around $600 for me, but I would go with a HD 7850 or higher if you want to max Battlefield 3 out and 700 watt PSU should do the trick. Amazon might have everything cheaper, but do you AMD or NVIDA GPU?
Also, do you need a keyboard and/or mouse? And if school work consists of video encoding, check out the i7. If not, i5. I went with i5 and video encoding is still good enough for me. =)
Max settings, a GTX 690 (1K though) but if you want it somewhere high then maybe a GTX 670 FTW from EVGA could do the trick, or just SLI if it comes to do that. But a duel GPU might be what your looking for but that goes over your budget as well. Not sure if any single GPU can get 120 FPS but I could be wrong. Check the GTX 670 FTW, I think it's like $400, around that range. But it should be able to do 60+, max settings. Check this out as well if you got time. =)
BF3 was coded to take advantage of dual vid cards so I would leave that option open. 750w psu is ideal for two of any of those cards down below seeing how it gives you plenty of headroom for extra drives, fans, over clocking, etc... and it's not that much more to leave the SLI option open for later on along with the option to over clock.
Twin Frozr IV: 20°C Cooler and 11.7dB Quieter than Reference Board
The MSI GTX 670 Power Edition is equipped with MSI's latest Twin Frozr IV Thermal Design. MSI's exclusive Dust Removal technology automatically reverses the fans at startup to prevent dust build-up dust and optimize the cooling module's ability to dissipate heat.
Patented Propeller Blade technology provides 20% more air flow over conventional fans and increases the effective cooling area. When combined with dual 8 cm temperature-controlled fans, SuperPipe technology, and a nickel-plated copper base, temperatures are effectively reduced by up to 20°C and noise by 11.7dB!
MSI's GTX 670 Power Edition uses the famous Twin Frozr IV cooler from the MSI Lightning and comes with a large clock speed boost out of the box, making its default clock speed even higher than GTX 680 stock clocks. MSI is asking a $30 price premium for their card, which doesn't look unreasonable, given the improved cooling and higher clocks.When you consider the free game and current rebate i think it's the best buy right now. Check this monster out (670 PE OC) = better overclocking http://www.hardwarecanucks.com/forum/hardware-canucks-r...