That is a great power supply you've picked out there, but it's also more than you need. With that setup you mentioned, you can easily get by with an Antec 400W and save some cash. The only thing you'd need a 480W PSU for is something like the Nvidia 6800Ultra card or if you had 4+ hard drives.
Of course, if you plan to upgrade this computer in a few years, your PSU will be ready to handle bigger and badder video cards, so that's a plus.
And stay away from Geforce FX. Definitely go with peoples' reccomendations of a 6600GT or 9800Pro.