Is 500W enough for this PC?

more then enough, you won't break 200w with that set up.

This is a nice online tool for calculating power needs for your PC, with plenty of variable options. Keep in mind that its not exact, but should give you a close approximation.

http://extreme.outervision.com/psucalculatorlite.jsp

The other thing to keep in mind is that you want some headroom in wattage. Cheaper PSU's can wind up producing a lot fewer watts than they say (I had a 700W PSU that burned out after less than a year, when the max power load for my system was around 625W). The better the PSU, the less headroom you need.

No worries with that psu and specs!