That is a very interesting target.
Did you already check this site?
http://www.nic.funet.fi/pub/mac/unix/00Index
I did not try anything myself right now, but may be some files could be helpful for Linux setup.
Another interesting setup might be MiniVMac for PPC/SheepShaver.
For Linux, I prefer to run MiniVMac from a SheepShaver hardfile, because it is pretty simple to copy files to or from it as you can open a small disk image with DiskCopy or MiniVmac alternatively.
SS also comes in handy, if you have to decompress some files for MiniVMac, done with Stuffit5 or 7.
If you wold like to take a look at my MiniVMac files for SheepShaver, they are here:
http://www.mediafire.com/download.php?xmovodaizune49b
Better don't open your MiniVMac boot disk with DiskCopy, because it seems to make it unbootable for MiniVMac.
Best wishes!