What you need, is that Siamese case that was available some years back.
It could house some seven mainboards, some of them even Amiga formfactor....
I rebuilt an old server housing once to put three mainboards in it.
I bet if you look around on eBay you can find tons of old servers that can hold at least some of your boxes.
Did they ever actually ship any of those??? IIRC, they never got past the 'prototype' stages... Or was that just the Siamese PCI? Anyway, there were two versions, one for upto seven motherboards and antoher for just three. Both, I believe, incl. special mounting plate (and backplane) for an A4000D and/or A4000T. I thought they were pretty cool idea... It's ashame they never took off.
