Thumbs up on this projet!!
You know ...after your initial post, every time I look at my H3 I start to see how your idea would look really good (as a 2-dr). How are your fabrication skills? LOL. It would be a really simple shortening job in comparison to some street rod projects. But it's the same kind of work as a street rod where you're shortening the frame and body. Re-work part of the interior.
If you haven't done projects like this, maybe you can ask around who the old-timer street rod guys are in your area. There are quite a few out there. Esp up in Detroit I bet there are tons of street rod guys. There was a time in the early 90's when hard-core street rodding was really hot. At the time I was the young guy in the crowd who did a lot of welding and the more grunt-ier work. But I learned a ton. Well these guys are now retired and get together regularly for lunches, etc. Most of the guys I know who are retired, have pretty nice shops too full of tools, welders, benders etc that don't get used much anymore (if you don't have a work area). If you are a good fabricator, go for it. If not, try to befriend one of these street rod guys in like his 60's or early 70's who's got ambition and wouldn't mind getting involved in a project ..more from a mentoring standpoint. ...and not too worried about money, or getting paid for every hour. (you do the grunt work). They might really enjoy getting into a project where they can use their experience and you do the work LOL. If you had to pay someone for the whole job, you would be talking a lot of money. Of course, if you didn't mind forking out some money to have a guy rough it out for you, that could make it easier too. Esp now heading into winter (lot of shops don't mind taking on a long-term winter project to keep their workers busy when crash work gets low).
I think I'd start by figuring out the side glass size and scout the junkyards for a piece that matches close to what you need. That's the one component you can't easily fabricate -- You can't cut tempered glass. There were 2-dr troopers and explorers, Blazers, etc. It needs to be relatively short. These old country salvage yards where they don't crush everything are the place to go. You actually COULD fabricate that piece if you wanted to jump through a lot of hoops. Or I'm sure you can custom-order a piece of curved glass too (I bet there are places). In my professional career I used to call on a major glass factory doing mechanical/engineering work for them. I've walked through their tempering ovens a number of times where they curve glass and temper it afterwards. (Correction, you walk on a cat walk *along-side* the oven and peer inside through the inspection glass -- ha ha). What they do is have an in-house fabricator make up a frame out of metal rod of the radius the glass needs to be. It's really simple; they just casually bend some 3/8" rod the radius the finished glass needs to be, and weld them as curved supports under the flat glass (they start with), about every 6" or so apart to 'catch' the glass when it begins to melt. After it melts to the curve it needs to be it gets tempered with compressed air that shoots out of jets as the glass moves along a conveyor belt (steel belt) in the melting/temporing oven. You gotta select the right color tinting too. But it's not that high-tech actually.
I used to call on and do engineering projects for factories of all types: Food, automotive, ag, plastics, you name it ..for 20+ years and was good friends with plant managers. In factories, most of the time they're doing something nobody has really done so it's like: "...here's what we want to do, what are your ideas to get there?" Since I was their 'solutions-guy' we had good relationships. They would always show me what they were doing and new projects they were working on (or things we were figuring out for them). At the end of a tour it would usually end with a "...but this is all proprietary information so don't tell anyone." lol. So if you have questions, maybe I could provide some insight.
So what are your next steps, anyway?