I know that was satire, but a micro PC might be a good solution for him. With a really small PC, the tiny Mac Mini and a decent KVM switch he'd be down to two sets of accessories and savea little space. Plus the PC could dual boot an older OS (or some free DOS solution) alongdside a more modern OS.
Then, of course you set up the Mac Mini to dual boot OSX and MorphOS. Then you've got five OS' (unless you want to throw Linux on to one of these as well).
Since you can't put a PPC Mac into the Amiga, you're going to have two sets of displays and input devices anyway. This setup would be more flexible and capable.
I wasn't entirely kidding .. I did specifically find one that would fit in a 5.25 drive bay. =]
