> Is there also some Linux that comes on a CD ISO or is that too small?

The Gentoo and the Crux images I linked to are CD ISO files. For Debian see there:

http://cdimage.debian.org/debian-cd/6.0.2.1/powerpc/iso-cd/ (Squeeze)
http://cdimage.debian.org/cdimage/weekly-builds/powerpc/iso-cd/ (Testing/Wheezy)