I suggest a 4 post over 2. The 2 needs X concrete under it for an anchor, where the 4 post works with less. The 2 post once installed is stuck there, forever. A 4 post is movable, but doesn't allow a vehicle to be lifted as high as a 2 post. Either way plan on 10' walls with (depending how many door) the lift placed in center door. Myself i would have built the garage around what ever lift you chose, not the lift around the garage.