check out the Landy section of
www.pirate4x4.com Theres a caged landy/disco along there every now and again, and being the yanks, they often go exo.
Ife exo caged the zook, and if you're ever in woods, or up close to stuff its great, you can just lean the car on it and do no damage...sweet!
Not as good as a diagonally braced internal cage in a hard roll I guess, but a damn sight tougher than the original body. Better still if you can sandwich plate thru the body and put a diagonal brace in.