Hi Julian
Well, they work extremely well in the sand, aren't bad in mud or snow - worse than a Simex, probably similar to an MT, will increase your ground clearance and they are tough.
On the downside they're heavy, hard to get hold of, can be very expensive and will put increased loading on your wheel bearings, swivels and CVs. This is what they look like on an 80:
It's probably worth searching bush taxi and the other German forums if you want to see them on a 100.
You will want a 6.5" or 7" rim. Getting the offset right could be tricky; kingpin inclination means you'd ideally decrease offset to compensate for the extra height however this brings other problems with wheel-arch clearance and increased load on the wheel bearings. We ended up using hilux rims with 30mm spacers to reproduce the stock zero offset on an 80. In an ideal world we'd find a nice strong zero-offset 16x7 alloy at a reasonable price (the tricky bit) as spacers are a pain and the steel Hilux rims are quite heavy. Can't help you much on 100 series rims, but I know some of the lower spec 'General Area' cars came with narrow rims, so there may be an OEM solution.
Balancing these was a challenge. Conventional rim weights just didn't work, so we ended up going for Dyna-bead style 'dynamic balancing' using airsoft pellets in one set and stainless steel ball bearings in the other both of which seemed to work, though the airsoft pellets do gradually turn to dust.
Hope this helps,
Toby
1990 HDJ80
1994 HDJ80