So, first a little history lesson. The stock caster was negative for manual steering. And the stock camber was positive. The reason for that was that the stock tires were bias ply. Fast forward and bit and bias ply's went away, replaced with radials. Radials have better grip, but different handling and wear characteristics. So, negative camber, and positive caster. If you run radials with the stock alignment settings, you get some pretty awful handling and road feel. Also, the factory torsion bars left these cars pretty undersprung. Part of that was the whole "riding on a cloud" 70's suspension feel, part of it was the rock hard bias plys. Add some traction and you get a whole lot of body roll, which is why you probably want sway bars. More traction = more force applied to the suspension = higher wheel rates to control the suspension.
Anyway. Most of the tubular UCA's have additional caster built in, it's usually an extra 2-3*. It depends on ride height and some of your other settings as well, but you shouldn't have much trouble getting around +5* caster with those UCA's. Which might be actually be on the high end of what you want with manual steering for a cruiser.
As for the torsion bars, it really depends. Ride quality is a pretty subjective thing. I run 1.12" torsion bars on my Duster, and I also run a 1.125" Hellwig front sway bar and a 7/8" Hellwig rear sway bar. I run Hotchkis Fox shocks on it, they do a little better with the larger bars than the Bilsteins (which are still a great shock!). With that set up the ride quality really isn't all that different than most modern performance muscle cars. It's maybe only a little stiffer than the 2013 Mustang with premium suspension my wife had for awhile, which is softer than what they run on say a new Boss 302 or other higher performance cars.
Honestly, with a set of 1.03's and Bilstein RCD's I don't think your ride would be any more uncomfortable than your average new commuter, Honda Civic, Corolla, etc. But it will not feel like an old 70's musclecar, so it really depends on what you're after. I ran 1" torsion bars on my Duster for a bit with a set of Bilsteins, I found them to be too soft for my liking. Big improvement over stock, but still pretty soft. But obviously I prefer stiffer suspension and will sacrifice some comfort for handling.
Here's the stock alignment specs. Do not use these for radial tires!!!
And here are some recommendations for radial tires. The SKOSH chart is a great starting point, I think the caster numbers are a little conservative, but they're actually not bad if you're using them with manual steering. I'd probably add +1* of caster across the board even with manual steering, and for power steering more like an additional +1.5* to 2*. Most modern cars run +7* or more for caster for their factory spec, of course it does vary a bit with suspension type/application.
