Yes, a 500w 24pin will be fine.
However, you must buy quality, not the best deal! A cheap PSU can lead to the destruction of your entire system, or, simply give out too soon, requiring replacement. A cheap PSU might be listed to have the wattage required for a GPU, but actually not have the proper Amps to do so.
So, go for a trusted brand, like Seasonic, Corsair, XFX. Steer clear of Thermaltake, Antec, Raidmax, and the like.