What budget is required?
The key is the diesel requirement, I suggest buying a gasser and doing a diesel swap. You pay alot more a good condition diesel than an excellent condition gasser. If I were to list my 1990 turbo diesel g with all the options available at the time like recaro heated seats, burl walnut trim, power windows. I would ask at least $25,000. It has a fully rebuilt 617A, all the major jobs have been done, larger exhaust, saddle tanks, wheel bearings, drag link and tie rod bar, rotors, brakes anyway a whole list of stuff including all the little annoying jobs like wiper spindles. The price I mentioned is just what I have into it without my time / labour (not for sale just trying to give you an idea). Expect to spend time and $$$ with any G to bring it to your liking.
Well having had a LWB diesel G-wagen, I can say that power is a big concern for highway climbs over 6% and mountain driving. The diesel is nice in that it is more efficient than the gasser equivalent like a 280GE which gives you more range for the backcountry. Having had a 300GD LWB and a G500, the choice is easy for me, I would not go back. I would only consider a diesel if the G was a SWB or cabrio as the weight to power ratio is a little more favorable.
Hmmmm. I can see that I have a lot to consider, and additional research to do. No time table established, but I would like to consider a GWagen...
Meanwhile, I'll drive my 80.
Parts for the pre 2002 Gwagens will always be available through our specialty shops like Eurotruck and Fourbyfourclub, it will just take longer and cost a bit more to get them stateside.