I have my list ready to go to build my new pc .........except the power supply......I want to see if anyone already has two evga gtx 680s in SLI in their build. Will a corsair HX750 750watt power supply work for SLI?
Yes it'll be perfectly fine. As long as it has enough connections though. A HX750 is rather expensive for its price, considering an AX850 which is fully modular is only like $160. An X-850 from Seasonic, top of the line stuff, is also only $149.99 after rebates.
A 750W power supply would definitely work, however it is always best to run under 80% PSU capacity to maximize PSU longevity. If you already have the 750W PSU, use it, but if you are purchasing a new one, I would go with 850W.