> the final ibooks use airport extreme, as did the 1.5 mac mini, and indeed
> the 1.42Mhz G4 and as far as I can tell all the G5s...

Yes, the internal WiFi, if installed, is of the AirPort Extreme kind in the following MorphOS-supported PPC Macs:

- eMac: all
- iBook G4: all
- PowerBook G4 Aluminum: all
- Mac mini G4: all
- PowerMac G4: FW800
- PowerMac G5: all