8'door shouldn't be a problem really!
Back when,most home garages had them,and people still managed to get their huge fullsize 50's cars in and out
I have all 10' roll-up doors,except for one 10'x10'-6"high barn door to get my motorhome in.It's tight.
You might consider a barn style or sliding style for more inside room.
With a door at each end,you never have to back up!
Only downside is the doors ruin usable wall space!
Mike.
