As we've read up more on Vaulting, we discovered that it is highly recommended to practice your moves initially on a vaulting barrel. This allows the vaulter to get more practice time in without burning out your horse. It also allows for making mistakes without hurting the horse--such as learning to land lightly after a jump; if there is a loud booming sound when you land on the metal barrel, you're probably not ready to perform that move on your horse yet!
After discussing whether we should get the barrel or the vaulting surcingle first (both are pretty pricey!), Kid 3 thought it would be better to get the barrel, both for the reasons cited above and because she felt she could practice with greater intensity on the barrel than on Honey Jo, thereby helping her to stay warmer this winter. This is important because she has to dress lightly. It's difficult to vault with warm, bulky clothes on. It's also difficult to reach maximum flexibility if you are shivering.
Lance at LB Vaulting Barrels was super informative and friendly. His kids participate with Technique Equestrian Vaulting Club in Saratoga Springs, Utah. That's the closest vaulting club to us--about a four hour drive from Rexburg. Lance invited Kid 3 to participate in any of their vaulting club events. He says that the vaulting community really works together. If you want to participate in an event but don't want the expense or hassle of transporting your horse across the country for the typically two brief 1-minute performances, you can usually rent someone else's horse to perform on.