Fastest OS9 machine would be QS or 1st revision MDD with a 3rd part CPU. You can stuff a 1.4ghz in a MDD (mine has a dual 1.33) and 1.8Ghz in a QS. Anything more then 1.5GB of RAM is wasted so either machine could have MAX RAM. A Radeon 9000 is the fastest GPU you can use.
The beauty of OS 9 is that even a 1Ghz G4 CPU is speedy as hell.
The beauty of OS 9 is that even a 1Ghz G4 CPU is speedy as hell.