This is 28' with a 16' door, riding mower, misc other stuff hiding behind the truck. Left of the car is the engine hoist, big battery charger, fuel jugs, blast cabinet, sliding miter work table, "stuff".
Go as big as you can. Square footage wise it is the least expensive part of the house build. We went 34 x 56 and have plenty of room to maneuver around even when we pull our Dually 4 door in.