I don't know your intended use for your storage building or how big you might need. Invariably, most people seem to wish they had a larger shed. Are you planning to build another pole-barn type shed or do you just want something to sit on top or the cement slab? Different companies make buildings for each purpose. Also are you limited by local codes for wind and snow loads on buildings. If you could give me a few specifics, I may have some suggestions.