Josh uses the McDavid A101R ankle brace in his Answer bindings on both ankles. Jeremy uses the same brace on one ankle. Josh started using Hinge-Tech, because they were the only bindings that he could get the braces in without great difficulty. I highly recommend the McDavid A101R brace. It has nylon stiffeners in it that provide pretty good support. After three serious ankle injuries this brace is the one that gave enough stability and support to keep the kid on the water.
Josh says that the Answer bindings are the best bindings ever. My biggest concern is that with the braces on, he never comes out of his bindings. Long term goal is to strengthen the ankles to the point that braces are no longer necessary.