Thanks!
I have replacement leaf perchs that you can just bolt down to hold them in place. Then for an extra measure just run them by a buddy with a welded or muffler shop for a quick weld bead on them.
Yes we only do them in fiberglass, I find fiberglass to be the right balance between lightweight and durable, plenty strong for off-road terrain. Fiberglass actually handles "contact" well. Keep in mind when the term fiberglass is used, it really mean fiber reinforced plastic. Because plastic has some elasticity, it can take a hit and just pop back that would leave a dent in an aluminum or steel tubbed trailers.
On my M-Series / M416 style tubs you have the frame under the tub to protect it in ditch and ledge drop off situations. On my J-Series / Jeep style tubs the body is more exposed, although below are examples for abusing J-Series tubs with no damage.
How about rolling one, no damage
Ditch crossings dragging the back, minor scratches
About 20 seconds in on this video, dropping off a ledge, dragging the back, not even a scratch
[video=youtube;flM5ZbG9aVU]http://www.youtube.com/watch?v=flM5ZbG9aVU[/video]