Sorry for the confusion! Yes, by O-ring I ment loose ring, down here that's what everyone calls them, or just general "snaffle" means one aswell. Basically what Sorrelhorse posted, but without the fancy colors. :) (Though I do admit I like them too!)
I think you've misunderstood me on a few things. I did not try him in a hackamore because I believe bits are harsh, I just knew he was responsive to nose pressure on the ground, so I suggested to my sister (my equivalent to a trainer, she trains horses for a living) that we try one just to see how responsive he would be, which he responded tons better to.
I'll probably try backing after each session, like you suggested, and working with him in the snaffle on the ground aswell. I still may try the sidepull (Not a mechanical hackamore) for him to get used to my leg pressure in the saddle, as I imagine that would make it easier if I try to ride him in the snaffle someday.
All around horse is what I'm thinking for him, if he takes to barrels, he may someday replace my gelding. I do think I'll try a sidepull on him, though. Do you think this would work? Mustang Nylon Side Pull - Horse.com