Small comment on a chain mouth bit....they are definitely not as bad as you might think. I have ridden several horses who really like the flexibility and ability to conform to the tongue and lack of nutcracker action and very light bar pressure that a chain mouth offers. I also think it is a very quiet mouth peice for the horse since only the outside links move with the shanks and is comfortable to pack. Think about when you were in school and put your necklace in your mouth while you worked...I know its silly to think about like that, but there is a place for them...
This is the type I mean...Not the "mule chain" or bicycle chain mouths as they are called around here.
Reinsman Large Chain Mouth Bits 532 - PFI Western Store