I found some used pallet rack units locally and they were perfect for my 24' X 25' two bay shop.
Just a few days ago, I made bi-fold cabinet doors to cover the lower shelf. They swing out and fold to give access to the lower shelf. I'll make another set of doors for the other unit. Anyway, I couldn't be happier with the size and strength of the pallet rack units and the bi-fold doors make a nice place to decorate the shop with some signage. Watch the video
HERE.