I found this new 'Rancher' western curb bit that comes in a hard to find 5.5" mouthpiece. It has loose sides for lateral cue, a copper roller and is fairly light weight (I've never used an aluminum bit before, not sure how I feel about that) and I would use it with a flat curb strap.
They look severe, however, after reading the site content (which, of course, says they are wonderful) it does sounds mild after all, but with more control than a snaffle.
What are your opinions?
Here are a few more styles and a little video:
Winner's Circle Horse Supplies, Tack - Mikmar Bits
Thanks for your input!