any one card is not accurate.
you will be fine with anything up to a 6790 (AMD)
or a gtx 550Ti (nvidia)
anything else i would suggest a 600watt or more psu.
Actually it can run up to a GTX 560ti with an i7-920 or a AMD HD6870 + a i7-920 just fine. How do i know? That's my backup PSU i keep in my dads PC and i put the CX430 V2
and Antec EA430D in budget pc's i build for friends....
Anyways to OP. No problem and feel free to ask any questions when you have trouble. (also feel free to mark best answer)