Built this based on the stock sheet metal, some MiSUMi extrusions, track and brackets and some polycarbonate panels. Tried to keep it light. Tested with a very busy four hour program and no rattles and so far nothing has fallen off. Got the sliding door idea from the enclosure I saw at Tormach this last Summer. But I thought I'd try a smaller enclosure before going nuts and building a big one.
Note I also use nylon curtains that run on a track attached to the ceiling. They work great as a last catch for the wild stuff.