Errm.. you gonna be using this for gaming? If so take out that quadro...did you pick it because it was the most expensive?
OK here goes
Sound card: fine
Gfx card: 2x 8800Ultras
Youve also stated that the motherboard is the cpu....Im quite worried atm of you building this monster PC with your lack of knowledge...
Motherboard...get like either a p35 chipset...DFI, asus and whatnot make good mobos...
Memory: Once again PC5300?!??! Get some corsair for cheap or OCZ or Mushkin...DDR2 Ofc
Case: ermmm..youre gonna get a nitrogen cooler? Do you even know what that is?!?