Brian, where are you? I'm in Tennessee and a VW fan as well. I just finished rehabbing an 86 Westy 2wd and am enjoying it lately.
The best diesel years are 2002/2003, the last year of the 7.3l. Unless you are independently wealthy, infinitely patient and enjoy breakdowns and bad news from mechanics I would strongly recommend you stay away from the 6.0l diesel engines. You can find one completely bulletproofed (which is where they take a 6.0 and make it reliable like a V10
) but they aren't cheap and maintenance will still always be much more than a gas motor. I'm sure some others will disagree but do yourself a favor and do your homework on the 6.0 before you get sold on one.
I will very soon have for sale a freshly converted 98 4wd Ford van, silver V10 with only 80k. It has not hit any classifieds yet but will when I finish it in a few weeks. I'm going in another direction instead of building it out. Anyway, if you're not interested you can definitely find what you are interested in around here.
Just read up here and on the Expedition Portal '2/4 wheel drive camper vans' section and you'll learn a ton.