Thanks for the great comments so far! Thought I'd post a few more pics since I've had a chance to work on the details
Here is the trailer. Weighs 8 lbs, which surprised me a bit. Not used to building metal models.
This is the flatbed with the CAT loaders. It weighs 7 lbs, which was more than I intended. The winch handles the load, however.
Hoist raised. This project turned out to be a lot of fun to build.
Hoist and winch controls. I don't have a 6 channel radio (and might have run out of room for the servos), so it's manual control.
The 8.4v, 3000mAh NiMH battery is forward of the landing gear and on the underside of the frame, where it just fit.
This is the motor and tipping mechanism I purchased from Carl Taylor at "piggytaylor.com" Works incredibly well.
Finally, the Warn winch from Tower Hobbies. I was surprised by how much it can either deadlift (when testing) or pull (when loading the trailer).