My brother in law runs a plumbing business. His work truck died last week. He is looking for either a Sprinter or a 3500 Chassis cab. He would like a box on the back. We are in southern California. Does anyone have any experience with a good dealer around this area? Also, what would it cost to have an outfitter add a box to one? We saw a sprinter in New Jersey that had a box added on the back but havent seen any on the west coast when looking online. Thanks in advance for your replies.