I would recommend the 'Corsair CMPSU-750HX'
(http://tinyurl.com/2brhlkw).
The Corsair Professional Series HX750W PSU utilizes advanced DC-to-DC
circuitry and meets 80 PLUS SILVER certification standards for up to 90%
energy-efficiency, reducing wasted energy and lowering the amount of
excess heat generated.




--
iniesta