Specious Workshop Garage Blueprint

I am looking to design a garage focused on being a workshop. I have ample space, 30 x 40, 1200 sq ft to be exact, and I want it to be free span. Skills required for this project include:
- Experience with large-scale design, particularly workshops and garages
- Knowledge of structural design, especially free span spaces

I expect to see proposed plans based on my initial design. Paramount is the design of the free span space.