I know what the requirements are..
But the PSU DOES have over 450w, don't misenturpret it. Watts = Volts*Amps.... This PSU has +12V1@18A, +12V2@16A for it's 12v rail...18 + 16 Amps = 34 Amps
34 * 12(volts) = 408 watts... now then, that means the PSU already has 408 watts on the 12 volt rail alone. Wattage really doesn't mean much, to tell you the truth..
Uhh, 8800GTX comes with two 4 pin molex to PCIe connectors to use. So you'll be fine..