what the hell do you need 1K watts for?!?
but back to your q:Reviews - Corsair HX1050 1050W Reviews - OCZ ZX 1000W
now back to your wattage, you do realize that PSUs take a big nose dive in efficiency when below 20% load. and at idle, where your rig will mostly be at, i cannot see more than 150 watts being used. so after you spend $200 for a silver/gold rated PSU; you will be getting the efficiency of a 80+ rated . . . not even bronze.
take a look at the "low load" tests in each review . .80% and 81%
edit: you can spend half the amount for a quality bronze 750 watt psu and have $100 towards another 7970.