Just my opinion, but if a shop guy recommends "You can put a 2" spacer" in the leafs (which I read as extended length shackles because a spacer in the axle mount actually lowers the car) the rest of his diagnosis is suspect. In stock form, mopar leafs when installed and at rest, will look like they are flat to the vast majority of people, even old school tech guys who are not intimate with mopars subtle differences.

LCA rebuild consists of only torsion bar bushings. Nothing else to do to them.

Sounds like you are considering replacing the entire upper control arm instead of just ball joints. Not necessary, but if that's the way you want to go, cool.

Frankly, I'd get a second opinion from another shop, but the increasing difficulty in finding shops that know old stuff may make that an exercise in futility. I'd recommend you talk to guys at any nearby race tracks about who they use for alignments , suspension work, or even fabrication. I might trust a modern race shop more than an old shop guy, unless he had extensive mopar background.