I am currently constructing my first computer and have bought a 6800gt video card. In the future I will want to buy another of these and run them in sli mode but am unsure about how well the power supplies will cope with this. I have a 550 p4 processor and an asus p5nd2 deluxe motherboard. I was thinking of buying a thermaltake butterfly psu for 50 POUNDS will this work? I was interested in the thermaltake modualr power supplys but their not avaliable in the U.K. yet. Thanks for any help.