John Kalmbach has written here the formula for finding a dealership that is used to handling fleets of vans with all their permutaions. I don't know how you'd search for it. Maybe PM him?
One way to locate Ford Dealers near you is to go to; https://www.fleet.ford.com/dealer_locators/default.asp . Enter your zip code and select "Business Preferred Network - Service Centers". You'll get a list of several dealers in your area. Fleet Dealers are usually better equipped to work on SMB's because they typically have more experience with diesel engines and are use to working with Ford vehicles that have been upfitted.