A 30 gallon drum might also work with the Jumbo Joe but you'll also end up with a rather tall smoke chamber but can be perfect for hanging ribs, for instance.
I do that with my 16 gallon drum sitting on a Smokey Joe. I can hang up to 6 racks of ribs on a single rod. That's what I primarily use that drum for.
....UDS....Mini-WSM....Midi-WSM....Mod-ECB....22.5-OTG....34"wood fired pizza oven....