Debian or Yellow Dog.
I think Debian Woody/Sarge work no problem, for Debian Etch and newer you may need a newer kernel.
I have Woody/Sarge CDs if you want it for starters. Etch you can get yourself.
The easy tick is to install woody, sarge then whatever else, by upgrading your distro.
http://amigaone-linux.sourceforge.net/
