Service Body

I've seen some fiberglass service bodies that closely resemble a stock bed. NOT cheap, though.

Lyle

Google is your friend!

Google - Fifth Wheel Towing Body

Foolish me. I was looking on this site thinking one of these would work and the prices don't seem bad. I should have known. LOL

There are some low sided service bodies out there. A friend of mine that owns his own car lots bought an F-350 with the regular service body that had been wrecked. He had one of the guys in his shop repair the body work to the cab and remove the damaged body. He then took it to a shop that specialized in service bodies and had a low sided body installed along with a gooseneck hitch. He used this truck for several years to tow one of those 4 car trailers to move cars between his car lots. This truck set up this way would also work to tow a fiver. The bed sides, from what I remember, were actually lower than a standard pick-up bed.

look up cm truck beds you want the tm model

Many companies make them. Most are pretty expensive.
Highwayman
or Douglas

There can be a few problems with using a service body. Your ins. may want you to get a commercial policy, some states require you register (and pay more) for commercial plates, and some city's won't allow you into some parts of town during certain hours.
I agree it would be a nice way to go though. Some of them are built and shaped almost just like normal beds so they blend nicely with the cab.