with a 750w PSU from either corsair or nzxt (both are good) you can OC your CPU, RAM, and video card. the system has an OC i7 CPU and GTX 460 in SLI. they hardly broke 500w in a stress test.
FYI. the antec 750w true powers are on sale on newegg.
Test System Specs- Intel Core i7 920 (Overclocked @ 3.70GHz)
- x3 2GB G.Skill DDR3 PC3-12800 (CAS 9-9-9-24)
P6T Deluxe (Intel X58)- OCZ GameXStream (700 watt)