Another chassis cab with a "pickup" bed is the Fontaine Modification Classic Traveler. The composite bed is swoopier than a stock Ford bed, and somewhere I heard the base price is around $7,000. The main advantage - other than style and looks - is the top of the bedrails is lower than a pickup, so it can tow some 5ers that are too low for an F-450 with a normal pickup bed.
Their conversion facility is about 125 miles from KTP, so they haul your truck there on a flatbed, then haul it back to KTP and give it back to Ford for shipment to your dealer.
http://www.fontainemod.com/ClassicTraveler.asp
