That one is a low port barrel comfort snaffle by Myler. This is what I used for training. Very effective, and my horse loved it. http://www.horsemall.net/images/HBTM...rt89_20065.jpg
Low port barrel with shanks. Also a Myler. They're virtually the same mouthpiece, but one works with direct contact and one works with leverage. The shanks are not very long on the curb bit, but with a seasoned horse you shouldn't really need longer shanks or a higher port to get the desired results. If you do, however, here's what it should look like: http://www.bitsnmore.com/images/cata...y89-11435b.jpg
This bit has a high port and long shanks, and would require mimimum hand movement. However, it can be pretty severe if not used properly. This is also a Myler.
Whatever style bit you decide would work best, I suggest a Myler bit. They're the most humane and effective bits on the market, in my opinion. They're expensive, but you can get them used on Ebay
for a huge discount. I sold off a bunch of my old bits, and I sold a $120 Myler bit for $70. So take a look there.