I have had 6 of them; my first in 1993 a 94, then a 96, 97.5, 99. 2002 and finally the 2006 Alpha; in fact I had it with me in Salt lake last year. Wonderful rigs as long as they are accepted as a big fuel hungry frumpy piece. I owner the same model that you are considering and put 50K miles on her and then a friend purchased her putting another 25K miles on her. The service and repairs remained modest and is a rig that IMO can be worked on my most.
The 1994 was N/A and I gave her to Gale Bank to create a turbo system off her; it was my first as such enjoyable however full of issues. The 1996 was factory turbo and better however the A/C was the pits, the 1997.5 was the first wonderful rig on all levels and then the 2002 was even better however the 2006 Alpha is the “only” way to go if able.
The lack of dealer network is an issue however parts are available as the primary rig is still being built; just not for the civilian market.
Lastly; the H1 is a slightly softened military rig from the ground up however the H2 and H3 were GM staple pieces with alternate sheet metal and badges. No less cool but rather they played to a different market.
Takes care
Shadowman