How do you overclock a PSU.! Oh ok, must be a typo for CPU.. Your video card is fine till you don't list your game titles you intent on playing and the settings you wish to play on.. I'd recommend you on getting a quad core.. The 955 BE is a great deal to miss.. Being from the black edition family, you can easily overclock it by increasing the multiplier and core voltage.. For your current listing and even considering the 955 BE and overclocking, a good 550 watt unit will suffice.. For that I'll recommend the corsair vx 550W.. Although personally, i like to be very sure while buying a PSU since its one of the most important and integral part of a build.. So i'd have personally gone for a seasonic x-650.. The full modular design takes care of the cable management and its 80+ gold certification says enough for its efficiency.. Reviews around will show you its excellency with voltage stability etc..etc..etc.. Yeah 650W will be overkill for your current rig and pricing is slightly high but it takes care of most of your future upgrades and more importantly gives you peace of mind..