My rig (C) is 10'9". Went with an 11' door on the front to keep the garage from being too tall for the surrounding buildings. If I ever get another rig it will be smaller anyway. I also left the option of installing a 12' sliding door on the side if I ever do need a taller door for storing a larger RV.
The RV door is manual but the other two doors have new openers attached to the side. Those are great as there are no chains or belts and the doors go completely up out of the way.
It's two story so I left the floor open on the second story over the RV bay so I can walk around and work on the roof inside out of the weather if I want.
Floor will be poured in the spring.