@ -D-
I've actually heard it's possible to stuff a BlizzPPC and BVision into the desktop case. Can't confirm it though.
@ Mr_B
If money is no object, and the above is true, that's probably what you should go for. Put a network card in the PCMCIA slot, and you've got a powerhouse luggable machine. You should probably leave the trapdoor off and keep a desk fan aimed at the machine...
As for power, I ran a 1200 w/ 060, SCSI, external floppy, and 3.5" HD on an A500 supply before I towered it up.