The Quadfather with the 8800GTX SLI won't boot into windows with less than a 700W PSU but 700W and up will do the job just fine. I'd say that the 2KW would run two of those setups with ease.
Phenom II 940 Black Edition quad core @ 3.5Ghz
2x1 gig OCZ PC26400 Platinum, 2x1gig GSkill PC26400
Upcoming EVGA GTX470
Some other stuff,
Even more stuff,
If the automobile had followed the same development cycle as the computer, a Rolls-Royce would today cost $100, get a million miles per gallon, and explode once a year, killing everyone inside. --Robert X. Cringely, InfoWorld magazine