I ended up buying the 9600.  The 9200 I was considering was a flashed PC AGP version.  The 9600 that I bought is a genuine apple part.  Its going into my MDD Dual 867.

I get the point about them both being older cards but I am still using my MDD dual 867 and its all the power I need. I'm not one of those people that needs the latest and the greatest. My mac suits me in every way other than video. I'm still using the stock 32MB Nvidia Geforce 4 and it leaves a lot to be desired at 1680x1050 as it uses every bit of the vram to run that res in millions of colours..

I am also really looking forward to core image. The seller even claims the 9600 supports core animation!
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