I would call the 1.06 torsion bars are not "light" . I'd equate them to about a 750 lbs spring or a little more in a 66-70 Mustang or Camaro.
The hollow sway bars that Hotchkis and Hellwig makes are have slightly less rate than a solid sway bar. But they weigh 5-7 lbs less. When you get to a 1 1/8 or 1 1/4" sway bars, they are very heavy. Both of those brands offer adjustable rear sway bars. I really like the idea of an adjustable rear bar and hollow bars.
Hotchkis offers rear leaf spring setups for handling with a stiff rigid front segment to resist wrap up and axle hop under braking. They claim their springs are lighter as a whole than a stock set. Hotchkis also found that moving the front spring eye up reduced rear roll steer. They sell a front spring hanger with a lowering postion. Dr Diff also sells a lowered hanger that is moves the springs inward for more tire clearance.
I would agree, 1.06" bars are not "light". I run 1.12" torsion bars on my Challenger and had to get drop spindles to get the ride height right. Probably not an issue with 1.06" bars with a BB as the nose will be heavier, I have a 318/904 in my car so I should be a few hundred pounds lighter with the engine combo. Then again, my car is a '72 so its probably heavier to start with. I'd think you *should* be safe with 1.06" bars unless you really want to put the nose in the weeds.
What do you plan to do with the car? Street driving, autocross, road race? I'm not one to talk, I'd put the 1.12" bars in my car again if I had the chance to do it over, but just be aware that there might be other things you need to do if you go really big. Also, I like my cars to ride pretty stiff, if this is just a street driver, you may not want to even go 1.06". I'm sure there's a lot of people that wouldn't like how my car rides on the street.