NZXT Precise 1200W Power Supply Review
 

To put it simply, the NZXT Precise 1200W Power Supply is superb. The voltage regulation is way above par, the overall build quality is very good, and it has a simple understated design without any gawdy extras. Anyone who has a huge, power hungry computer may be interested in this unit, but unless your middle name is ''Overkill'', then it will honestly be a lot more power than you could possibly need.

http://www.bigbruin.com/2007/nzxtprecise_1

an Overclocked Quad Core with HD 2900 XT in CF doesn't even come close to 1000W....

At 80% efficiency 1200x80%=960 Watts :)
Or, 240Watts of waste.

I run C2D@2.8+8800GTX at 240W (read at wall socket)

that's the power of a whole system going to waste; if you manage to create full load on this PSU of 1200W