I bought a 6x12' enclosed trailer with 6'6" headroom a few years ago when I had several grain systems to wire and they were scattered all over the state. I built shelving and conduit racks inside and still had plenty of room for 25' of scaffolding sections and a 5kw generator. It was very handy to work out of. I would still have it but another sparky offered me more than I had in it and I wasn't doing too many grain systems anymore.