I have one I am selling. I got one of the smaller Rigid Worksite toolboxes, I paid like $200 from Home Depot for.
It fits perfect in the back of my TJ with lots of water proof storage. Still have it in good shape. Will let go of for cheap, only reason I am selling is I am putting the jeep back to daily driver.
http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053
Here is the link, fits perfect within the wheel wells. Let me know if this is what your looking for.
If you want something with drawers, AdrianSteel is the company who makes a lot of the storage for workvans etc. from the factory. At one point in time I was looking at outfitting an enclosed trailer for my fathers construction business and they had some pretty cool cabinet setups as well for cheap.
Hope that helps, Nic