South American 40s can be a can of worms on their own. Plenty of discussions and opinions on this forum if you search for them.
Owning a diesel in the states has been fairly straight forward. I was able to get a diesel title without a fuss. Maintenance parts are easy enough to find from the usual places: cruiser outfitters, Toyotapartsdeal.com, dealer, etc. But you won’t find parts at a small town napa so I have spares I take with me... though I probably roadtrip mine more than most.
I agree with the above - landcruisers are slow but the B engines are a special kind of slow. If you want the option to turbo down the road you will want to find a 3B.
40s are in general loud, hot, and slow moving. Another reasonable option would be to find a nice US spec 40 and drive it for awhile. If you decide you still want it slower and louder, a 3B would be easy enough to drop in.