I haven't had any problems bottoming my Bilstein RCD's. They used to advertise them for stock height or 1" lowered, although looking at PST's site I don't see the 1" lowered set anymore. Probably worth calling and asking. That said, I don't think the ones I actually have are the lowered set.
As far as them doing the job, they will. That's not to say they're the best option, but they do the job just fine. On my Duster I was running Bilstein's with 1.12" bars (300 lb/in wheel rate for A-bodies) and found that they did a good job. I had a chance to buy a mounted but not used set of non-adjustable Hotchkis Fox's for that car so I did, and I can say that the Hotchkis Fox's, even the non-adjustables, do a better job than the Bilstein's did on that car. It wasn't a night and day kind of difference, but it was noticeable. A little smoother on the lousy roads around here.
I haven't run the QA1's, so, no help there. The 1.18" torsion bars from Firm Feel have a 338 lb/in wheel rate, so, a lot stiffer than the E-body 1.12's which are 270 lb/in, and still a bit stiffer than the A-body 1.12" bars like I run on my Duster which are 300. I'm really happy with how the Duster handles and rides on the street, I think 300 lb/in is pretty close to perfect. But that car has a small block and a decent amount of things to lighten it, so, the 1.18's on an E-body might not be all that much stiffer for ride quality because of the extra weight. For a big block car I think they'd be the ticket. For a small block car you'd definitely want a good set of shocks to keep the ride quality reasonable on the street.