sort of the way my new one is designed. small jog out from wall then vaults to 14'.You can go with 10' sidewalls and scissor trusses to create the height you need without having warehouse-height sidewalls if aesthetics are an issue. I did this and I have plenty of height even with an F250 on the lift. If you don't intend to use a vaulted ceiling, go 12' sidewalls minimum.
I have 9' ceiling and a 4-post lift and can stack a number of combinations except my 1990 300ZX TT on top of a BMW 850i.
The object of my post is to encourage pre-existing garage owners to not rule out a lift due to ceiling height.
I believe that an 8.5 foot ceiling is the minimum needed to put a car on the lift and still have enough room to put one underneath.