Instead of a teeter or in addition to, you may want to build a wobble board. These are great for teaching pups to get used to surfaces that move and they can move in any direction and the board moves. I used this with my last litter and they loved it and my girl Sophie has been absolutely fearless about all the agility equipment.
Great suggestion and wonderful Idea. Its probably a better choice than I would have made for him. Also thanks for the link on how to build one.