Which PSU is better

Ok everyone I need your opinion for my new build, so far here is the build

CPU = AMD Phenom II 940

Mobo = Asus M4A79 Delux

GPU = HIS Hightech Radeon HD 4850 512MB 256-bit

HDD = WD 1tb Caviar Black

HDD = WD 320gb Caviar

I have been searching the reviews on PSU and I have narrowed it down to 3 different ones, if you could let me know which one would work best for my rig or suggest some other ones for me to check out.. thanks

Newegg.com - OCZ OCZ700MXSP 700W ATX12V V2.2 / EPS12V SLI Certified CrossFire Certified Modular Active PFC Power Supply - Pow..

Newegg.com - COOLER MASTER Real Power Pro RS-650-ACAA-A1 650W ATX Form Factor 12V V2.3 / SSI Standard EPS 12V V2.91 SLI Ce

Newegg.com - CORSAIR CMPSU-550VX 550W ATX12V V2.2 SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Compatible with Core.. rti..

Should I go with one higher then 550w and does it matter how many rails it hasdrkstorm37

Should I go with one higher then 550w and does it matter how many rails it hasdrkstorm37

That Corsair it's more than enough for that system.

[QUOTE="drkstorm37"]Should I go with one higher then 550w and does it matter how many rails it hasferret-gamer

Actually the VX-550W it's better, the only advantage of the HX-520W is that's modular.

It does not matter if one has 3 rails vs one with 1 rail?drkstorm37