I use an english hackamore on my paso fino. The previous owner rode him in a columbian headgear sometimes and a curb bit other times. When I got him home, he was an idiot in a triple jointed full cheek snaffle (my bit of choice). He kept putting his tongue over the bit and was totally distracted by the bit the whole time. I didn't want to ride him in a curb because he didn't steer very well. So, we went to the english hackamore. He loves it and so do I. He steers well and stops fine.

Here's a pic of an english hackamore-
http://www.valleyvet.com/ct_detail.html?PGGUID=d6dd6945-349f-4a3f-aa47-4c0fc34e5d87

It's funny though because when I go to take off the bridle, he will still open his mouth so that he can spit out the bit - even though the bit is no longer there.image