I think that when Travis and I get to work welding up sliders we might experiment a bit with an option. I hear ya'll on the interior space issue, but I figure I'll just leave the underbody hardware intact for the times when I really need interior space (like the semiannual all-family road trip). It may be a pain to move around but I probably won't be moving it all that often. Otherwise it's just me + my wife and a kid or two, or just me and bike or trail gear.
I'd like to fab up something that uses the existing bolts in the floor of the cargo area, and attaches to the grab handle holes (eliminating the handle) just for a little more lateral stability. I understand that in isolation, none of these threaded holes are particularly robust, but together I suspect they'll be more than adequate to support a 33" tire. By fabbing something up, at least I won't be dropping real coin on it if I decide I hate it.
Thanks for all the input. The links to the Mud threads are ones I'd found. Unfortunately, Jonesy's took theirs off the market (per an email with their main guy). Theirs was the best looking option, but was still $200+. I'll post up what we come up with if it's worth sharing.
1993 FZJ80: the Green Chile