Check out the Switch-N-Go system http://switchngo.com
We have been using these for over 6 years and would never consider any other again. One truck many different bodies. If they don't have a body for you they can make it or find someone who can. There are so many added benefits of having a bed that you can lower down to ground level and/or switch out in a matter of minutes. You owe it to yourself to check them out.