NO OPEN FIRMWARE HACKS NEEDED !Here is a disc image that can be burned to a cd and booted to test if your machine is bootable to OS 9 without firmware hacks.
This is the same system folder I have been using when I manually install over target disk mode to do my initial testing to determine if a machine can even boot.
There are no extensions in this image. It will literally boot and that's about it. No applications or utilities installed.
If you boot this disc and are able to get to the desktop then your machine is bootable. This does not mean though that all hardware is supported and would work with a more full install though.
http://www.gnerder.com/files/BootTest.sit