Here's a liftgate that makes sense on a service body: The Tommy Gate Aluminum Liftgate, available in the standard and the G2 Hydraulic Dual Cylinder models. This makes sense because of how much lighter the aluminum model is versus the steel platform. Any weight savings behind the rear axle is a good thing!
This liftgate is mounted on a Harbor 9'x22"x41" Service Body with Stainless Steel Lids, a Window Guard and Spray Bedliner. Thanks to Kimberly at Harbor Truck Bodies for the shots.