Get the ASUS A8N32 - it's just as good if not better then any DFI. "Look on any "major" review or forum site and they will tell you the same thing." (Yes, the PCI slots are crowned) But, don't go SLI, it's a totally waste of money. Not worth it...
Buy a X1900XTX instead or wait until the next round of Videocards comes out at the end of the year...
Consider at least a 600W-850W PSU.