ok I decided against AIX as it is closed source software, but I found this:

"i've succesfully tried Gentoo PPC (only with serial console then you need minicom on serial1)
On Gentoo PPC you must choose ibmpower-ttyS0,9600 boot kernel."

from here: Install Fedora Linux on a IBM 9114-275 - Linux Forums

although being new to power pc I am not sure what he means by serial console and minicom? I assume it is not as easy as putting the discs into the drive? Can I learn how to do it?

Regards