We are specialized in prefab houses and I presume garage should be an easier task for us. Usually the houses we assembly have 2 or 3 garage doors... Have a look to our designer's site www.drummonddesigns.com and ask for Ben Larochelle.
We just finished a 3500 f² house in NH and he is now working on extension for and 18XX house in the same area. You know what, 2 garage spaces will be added on this pretty old house.