The AMD and the Radeon will draw a lot, but other than that, I dont see much power draw. Normally I would say 330w is a tad low but since it's Antec, I don't forsee any problems.
Are you going to have a lot of fans in the case though?
I have almost the same setup, but with a 9800 Pro. I bought a 420w from ThermalTake (Very good).
I took the liberty of stopping by newegg and found the Antec for $55
http://www.newegg.com/app/ViewProduc...103-906&depa=1
And the thermalTake for only $49.
http://www.newegg.com/app/ViewProduc...153-006&depa=1
More for less since you aren't paying for name. Read the reviews, look at the specs and make the decision for yourself.