If you decide to do a stick build, you can buy attic trusses for about the same price as non-attic ones. Dropping plywood into the attic trusses gives you lots of storage for very little extra money...and future expansion room.
If you have attic trusses in place, you have lots of inexpensive future expansion room to go up, not out, even if you don't finish the attic at first. Access can be through a hatch, pull down ladder/stairs, or more elaborate with stairs. Depends on future expansion plans and money. The last custom garage that we had built in NC had back stairs to get to the attic. Never finished the upstairs before moving, but the plan was to make it my wood shop.
The disadvantage of an attic is that you give up the height needed if you want to install a lift.
Matt
