Firm Feel, Just Suspension, Hotchkis and PST all make bars in the 1" to 1.06" range. Firm Feel offers 1" and 1.06" bars, Just Suspension has 1" bars, and Hotchkis and PST both make 1.03" bars.
All should be pretty close in spring rate, it does vary with manufacturer for a given size. The 1.06" bars would be a bit stiffer.
I have 1.12" Firm Feel bars on my small block Challenger, although they ride stiffer than most would like I think. Hotchkis has had some issues with cars not being able to get enough ride height, the way they clocked their bars results in a VERY low ride height in the front unless they've changed it.
Just Suspension and PST sell their 1 and 1.03" bars for around $200, so over 100 bucks less then Firm Feel or Hotchkis.