for the psu, go with corsair 620hx, it will run OC'd GTX's and OC'd quad.
vista premium 64-bit, it does NOT lower gaming performance 30% gawd who told you that. maybe 8% max.
for the resolution SLI is not necessary, an ultra can handle it.
raptor is not a good idea, it is a tad faster than a 7200.10 drive, but simply not worth the price... and the WD 750gb is just as fast.
crucial ballistix and geil black dragon and ocz reaper and patriot EXtreme performance cas lat 4 are higher performing RAM