Congragulations!
You'll find there's many critics of the GM, and it is the "unwanted stepchild" of pickup diesels. But they do hold up very well to drivers with a binary foot. I've been playing with the 6.2/6.5 longer than the IH idi and was making them work in a fleet of tow trucks and service trucks. Thankfully to the US gov't being eyeball deep in these motors, there has been alot of improvement on parts. You can get complete ****** castings if you want to go stupid crazy. In order for the HUMVEE to keep running, there's a new design block that is almost unbreakable and ****** head castings that will graft on the 6.2/6.5. There are differences in the valve sizes, precup size, and injector angling, but if you run the same pair of heads you will be fine. I've been bolting together 6.2's and 6.5's motor combinations for years. As far a a turbo goes, its a necessity for these motors to get out of their own way. Without it, they're slower than a NA IH. If there is a choice between the Banks turbo kit or a GM factory kit, I'd go with the GM. imho, much better thought out and easier to get parts than the banks. Only problem with the GM factory setup is if you do have a AC setup, you will need to do some major work to get everything to fit. here's a pic of one of my morphodite trucks....