this site says you need only a 430w PSU.
I reccomemd any high quality PSU you can find on
psu tier list
I personally reccomemd the antec VP-450 as a PSU. It is the cheapest and best. Though only as a tier 3, I personally see it as a great budget PSU. Other PSUs like the EVGA 550 gold and XFX ts series PSUs are higher quality and better overall. The seasonic 450w PSU and 520w are also very good.