You might have trouble finding one that still works.
On mailing lists, it seems like Debian and Gentoo are still somewhat active with PowerPC. I use NetBSD/PReP port on my 7248-133 43P and even that is a little finicky.
gmane.linux.debian.ports.powerpc
Although, there's a lot of Mac PowerPC focus there, since those are the most common PowerPC machines.
I also have a box with, I think, CDs for AIX 3.2.2 and some applications like VisualAge C++ and SmallTalk. Also some book manuals for the RS/6000 F40. I don't have the F40, so was keeping it around until I found someone with one that wanted them and possibly to rip the CDs for preservation.