I've got Radeon 9550 now... I don't know how it compares to yours but it's definitely worse.
Just so you know, I managed to run Maya with Nvidia FX 5200 (which is MUCH, MUCH worse then yours) earlier with reasonable preformanse.
I also have 2.6 GHz on one core so I wouldn't worry about the CPU, and I've got 1 GB RAM DDR(1) so I'd say 3 GB DDR2 will do for a few years at least...
wellcome to SM :attn:
Benny