The problem I see with one entrance/exit is you will be moving vehicles around more than necessary to access the exit, unless you plan to make one large roll up door.
I've linked a U.S. company that makes all kinds of clear span buildings,barns, garages, etc. As I think of more I'll try to add them. Is there a reason you want a U.S. company?
https://mortonbuildings.com
Good luck with your project.
~ Steven