I think the NT would do well with a sidecar because it's substantial and not too tall. Plus it is bulletproof, which is important because when you have a sidecar you have enough things to fiddle with, without having to do desmo valve adjustments or replace pistons.
The tires are not as much of a concern. You can run normal motorcycle tires on the sidecar outfit. People just put on car tires for longer wear, since sidecars don't need to lean. The motorcycle tires will wear out faster in the center; they square off. But you won't feel the weird lump in the profile, because you aren't leaning so you don't have to roll across it.