Geforce recommends minimum 500W just for that video card. I don't need to consider other devices for more power?
500w for the entire PSU, not just the video card. it's also a recommendation for a bottom of the barrel PSU and like davcon stated, a quality unit would be more then enough. Something like the antec neo-eco 520w would offer plenty of power for a reasonable price.
Be careful here as all PSUs are not created equally. There is a big difference between a 500W Seasonic and any lesser brand, for example. With PSUs, you get what you pay for. Also, if you are going to spend a chunk of money, keep future use in mind (thus my earlier suggestion for a quality 650W PSU). 500W will meet your current needs just fine, but be sure to get a good one.
lol i have a similar specked machine which i cannibalized an hp to build and i used its 250 watt psu to power the system and it works =D the cables arnt long enough so its propped up inside the case on the hdd cage from the hp.