We've had a couple of threads with this sort of idea before, Someone made a thread about putting a u-ATX board inside his A500 case (I think the thread is still near the top of the community support forum or something like that). I have also toyed with the idea of using an A1200 case (nicest looking wedge style Amiga of them all IMO); for a while the keyboard was an issue but those keyrah things can be used (with some creative use of a dremel tool) with the USB ports cut off from the backplane of a m-ITX board. Plus with that small a board you can fit a graphics card inside aswell (as long as you can find one that isn't 10 storeys tall). though that would require a heavy duty PSU, much more than that pico thing.
