680i or 780i

ok so im looking to build a decent gaming pc. right now im looking at a Intel q6600, 4 gbs of 1066 ram, two 8800gt in sli, and a 680i motherboard.
my question is though is one will 1066 ram work in a motherboard thats memory standard is 800, and secondly i have heard that some of the 680i motherboard have problems with intel quad cores. one of the problems i have read about is that they sometimes boot up at the lowest possible multiplier. another thing is the graphics cards are pci 2.0 and i know they will work in a pci x16 slot but is their much performance gain from having them in a pci 2.0 slot? also should i wait for the geforce 9 series graphics cards to upgrade?