@BoingBoss
I'd like to see a picture of your A500 project. Years ago, I did contemplate putting my old A500 into a tower, but decided on towering my A1200 instead. I'd be very interested in seeing some pictures and/or an article on how you built it.
Not sure about the reliability issues you report though... My original A500 suffered a keyboard malfunction after a week (from new), but my A1200s are going strong despite both being over a decade old now and having both been generally hacked around and modified. The only problem I've had is with accelerator cards, not the actual machine itself.
I can't speak from experience with the A3000, but I don't recall anyone ever complaining about reliability issues there.