The drive through shop idea is a great one.If you are planning to raise the roof to get your trucks through,then and over-head crane might be a good option.I would imagine you would use it a great deal in conjunction with maintenance.A mate of mine has one in his Muffler shop,he was laughed at when he put it in because he generally deals with the other side of vehicles,but he makes good money on the side swapping gear boxes or removing camper bodies from R.Vs etc.