I think you're SOL here. Most kernel's assume that the system BIOS will correctly find the keyboard. If they have USB support compiled into them, they might find the mouse, but I'm not optomistic about the keyboard. I don't know if RH9 addresses this problem or not.
What I would do is pull the hard drive out, plop it into a box with working PS/2 ports, install Linux on that, be sure the USB stuff is working, and then put the disk back into the original box. Of course, that assumes you have another system handy...