as far as a "standardized platform that you can buy fully built and turn-key" how about the Scorpion MkIV? Foers Ibex? later model Nissan Patrol? Does the AEV Brute count? (i know it's a TJ with mods) I've even seen 80's vintage VW Syncro vans that, right out of the factory are remarkably versatile. The FZJ70 is totally rad.

Personally I'm stoked about anything versatile, even if it's not the most brutal rock crawler on earth.