I have never heard of a Radeon 9600 PCI.  Even if there really is one a GPU like that would be wasted on a 66mhz bus.  Even the 9200 will be wasted on a bus like that.

The 7000 is a good card for these machines.  Cheap, easy to find and you won't be wasting money on gpu power that the graphics bus will not be able to utilize. 
Mac mini C2D 1.83GHz - 2GB RAM - 200GB 7200rpm HD
Sawtooth w/G4 1GHz - 1GB RAM - SIIG SATA w/2x1TB HD
B&W w/G4 600MHz - 1GB RAM - 2x80GB HD
Sawtooth G4 400MHz - 512MB RAM - 40GB HD
Dell Ultrasharp 2007WFP 20" Widescreen LCD
2.94TB Total Storage