I am wanting to build a computer with this card its just right for me the problem is i don't know which power supply i should get. I am wanting something about 750W or bigger if it comes down two it. I want to have a big power supply, because i don't know if i will do crossfire. The lightning needs 2 8pin and 1 6pin.I don't want to waste money on buying the wrong psu. I am wondering if i should get a adapter for it or buy one with those pci-e pins.