[G4] G4 dual video upgrade

[David Gardner]

I have inherited a PowerMac G4 dual 500mhz with the standard ATI Rage 
128 AGP card. The recommended upgrade is to the ATI Radeon 9000 Pro Mac 
Edition, but those prices seem pretty high, as well as it being pretty 
rare, especially the 128mb version.

Is it possible to forget the AGP slot completely and run a PCI video 
card instead, but not PCIe of course, and if so, which higher end card 
would work best in this system?