Nine foot garage walls and Hoist?

Seems manufacture would tell you of mininum height. Heck if I could`nt stand under it I could`nt justify expense. And that would probably be a 12' mininum. I have a 10' ceiling and use a homemade gantry hoist. Anything else 4 jackstands. If you have 2 or more bays, go for it. With my 1 bay, it would probably be in the way, most of the time. ultimately your call.