I found a new set on Amazon, new for 150 used for 55. I was told by Apple about a year ago that I could not upgrade my PowerBook G4 to 10.6 from 10.3.9. I didn't inquire, but I suppose Apple could not sell me the Mac OS X 10.4 (Old Version) any more, anyway.
Since it is a little bit of money, before I buy 10.4, I would like to be sure it will work. Do you know of anybody with 10.3.9 successfully installing 10.4?
Sorry for getting back so late, but the forum was acting up on me for some reason.
Tiger will work on all G4 PB models. I did check first to be sure. The first released model can run up through 10.4.11 - the last Tiger version released.
You are right that you cannot upgrade to Snow Leopard because it requires an Intel processor.