Got the MacOS Tiger DVD (as supplied with ibooks, et al.) they
could lend me [I have a last-generation PPC ibook, so it's
fully licensed]
I've got a 15" PowerBook which came with 10.3 but I also have the
upgrade to 10.4
If you can get to SK17 0LU you can help yourself! Use my Mac so you
don't have to unload your Linux goodness.
While you are at it you can install Fink for me - I can't :-(
HTH
Sim