Go with a DFI Lanparty UT SLi-DR Mobo. Any dual core AMD you want would be fine, depending on how much you can spend, if you gonna overclock go with Opteron 165. Get a 7900GT/GTX. no need to sli the 6800, 7900 or even 7800 woops it by itself. This motherboard is ATX. so you case will support it. BTW wat type of PSU do you have. Because if later you choose to SLi ur new card, with the 7900s its recommended that you have at least 450 motherboard.