I guess I'm not understanding the problem too well here... but if you feel safer with a harsh bit, then my recommendation is a pelham. I would steer clear of any twisted wire bits, or even a slow twist bit - you can do very great damage if you don't have good hands.
(I am of the opinion that great riders should be able to ride any horse in any bit, but not need to resort to anything other than a snaffle... but that's just my opinion. And truly great riders are few and far between.)
On to the pelham - this gives you independence of rein. You can ride on just the snaffle rein, and then apply the curb rein as needed, this way you can save his mouth a little more. With something like a kimberwick, you are never riding off the curb rein... with the pelham you have a choice - ride on the snaffle, ride on the curb, or just enforce the curb as needed.
That's my 2 cents. Please feel free to PM me if you have questions, or I'll check back on this thread later.