I'm thing there were only two official 9200's. The Radeon 9200 Mac Edition Retail, and the OEM Xserve Radeon 9200LE, and I'm pretty sure it was PCI.
Some of the G4 Xserves shipped with a PCI card, I know some of them were Radeon 7000, but I was thinking you could BTO a G5 Xserve with a video card.
The Xserve G5 had PCI-X slots that are bankward compatible with 3.3v PCI.
As to the OS 9 drivers not loading for the card, it is likely that the card does not match in Device ID, or even in Name Space.
What you need is an IOReg dump from a Retail 9200 or a flashed one that works for OS 9, then you need to change the .properties of your card to match that one. After that the OS 9 driver should load.
A lot of times ATI made custom Names for the OEM cards so they would not match in name space with the Retail cards. Likely it was a support issue, OEM cards needed you to call Apple Care for support issues, and Retail cards were handled directly by ATI.
My OEM Radeon 9000 has a Name Property of ATY,PheonixParent. I think the Retail 9000 Mac edition had another name, also the Model property. That's the Parent, the you have to look at the children, the display connectors. The name property, and the compatible property.
If you can put the card in a computer with OS X installed and use IORegExporer to dump the properties of the card, or boot into Open Firmware and find the card in the device tree then do .properties on the Parent( ATY,XXXXXX ) and then do it again on one of the children( ATY,Dispaly_A ).
Or download the OS 9 PCIDDK and look at the card in IOreg and PCIPeak.
http://www.staticky.com/mirrors/ftp.apple.com/developer/Development_Kits/PCI_DDK_3.0.sit.hqxWe need a dump from your card and a retail card, then I should be able to tell you how to get your card working with the OS 9 drivers.
As to the other problem, I remember some touble with Acard's Fcode and ATI's Fcode, I think there was some type of workaround or maybe not.
May check Xlr8yourmac or OWC's old Xpostfacto forums for info on this.