So just adding a sway bar shouldn't really make the suspension stiffer all the time. It should primarily effect roll stiffness while cornering, and should basically have no effect at all if both the wheels are moving up and down at the same time. So, if adding the sway bar has made the car stiffer all the time you might want to check and make sure you're not getting some kind of binding with the motion of the sway bar.
I have larger 1.12" torsion bars on my Duster and have used the RCD Bilsteins and currently run Hotchkis Fox shocks in it (non adjustable version). The RCD's worked well, the Fox's do a bit better handling the 1.12's. That said, I think the smaller bars work great with the RCD's. I also ran RCD's on my Challenger with 1.12" bars, with the E-bodies the bars are longer so the wheel rate is lower (270 vs 300 lb/in). The RCD's were great on that car. The ride is more similar to a modern performance based car than the floaty, undersprung nonsense that was normal for these cars from the factory.
