I'm looking for a stepup bit from my smooth snaffle. My mare is only four and very sensitive so I'm not stepping up because she is not listening. I just want something with a little more lift and some breaks in the mouthpiece. I was thinking something like a junior cowhorse or something with a longer gag and short shank.

I really liked the Kerry Kelley Ticket bit for a transition bit. My mouthpiece is a 3-pc Bumpy. I know a lot of people like the Jr. Cowhorse, but all of my horses hated it.

I will second the KK Ticket bit. It is great for this. Leather or flat curb chain is my go to after having a snaffle on 

No need to change. For lift put your hand up by the ear and raise your hand.  Work on softening and one rein stop. You won't need more bit.