suse, mandrake, united linux i think
plus every distro which has support for ppc processor (mandrake, debian..)
But onlu the first ones are "supported" by ibm.
again, depends on what you like.
debian.org and so on...
Not yet but i will do it asap!
If you find me the debian binaries for iSeries i can make you a step by step
procedure to install linux on rs6000!