Cooler master gladiator 600 psu?

Your case is good but I don't trush from stock case, you need pure Psu from good brand like : seasonic, corsair, xfx, anteq.
Minimum psu from nvidia suggest 500W, in the reviewer power consumption idle 171W , fulload 386 and oc 425W. It's mean 500W pure PSU enough .. It's all depend your budget. www.hardocp.com/article/2011/07/11/gigabyte_gtx_560_ti_oc_video_card_review/8