if your cpu has o/c ability and you plan on overclocking both cpu and gpu i would recommend a 650w one like the xfx recommended above. if the o/c is limited to the gpu only then a 550w like xfx with 45A on the 12v rail will be enough!
Avoid corsair CX and CS series. They have cheap caps which can easily fail when under stress.
Stay with these brands: Antec, Coolermaster V series only, Corsair (AX, HX or TX only), EVGA SuperNova G2 series only, Seasonic or XFX
If you want a 650W version here an option: http://uk.pcpartpicker.com/part/xfx-power-supply-p1650xxxb9
if your cpu has o/c ability and you plan on overclocking both cpu and gpu i would recommend a 650w one like the xfx recommended above. if the o/c is limited to the gpu only then a 550w like xfx with 45A on the 12v rail will be enough!
Yes it may be more power hungry but still a 550W is enough. Its PCIE connectors and the amps is still sufficient enough. Although a 650 or 700W is better as it is further away from the max draw and allow higher overclocking..