live load values

[DB]

I want to build a 2nd floor on my shop. The shop is built into a hillside, the existing walls are 10 inch concrete retaining walls on 3 sides. It is 24 X25 feet. I want to span the 24 feet if reasonable cost, I can work with steel or wood. I can put a beam in for a 12 foot span if necessary.
The 2nd floor will be a woodshop, I do have 600 bd ft of hardwood to store in it plus at times I would like to park a vehicle in it.
What is typical live load value for this floor?[/b]

[mjpliv]

This is one for the engineers. Big loads and long spans.

I would actually consider a suspended concrete slab for this job. One 24' poured center beam with a monolitic floor slab poured in Q-decking.