Don't go SLI, it's a waste of money. It's a waste of money to pay for the motherboard company to tack an extra PCI slot on there and a waste to pay for another graphics card to slightly increase performance. Just get one good card, be it Nvidia or ATI, One of eithers top end models would be fine. Just start looking around DFI street for all the recommended parts, there's huge sections about what parts work well with DFI boards. Are you trying to build a whole new PC with some re-used parts or just getting a new motherboard?