Building on my experimentation with sidewall, I wanted to try a poured epoxy sidewall method as seen on skibuilders.com. A buddy working as a CNC operator at a startup let me come play around with heavy machinery for this one!
The idea is to cut a trench out of your wood core stock, in the shape of your board. Pour epoxy into that trench. When cured, plane down the whole thing and profile the thickness. This method, in my humble opinion, yields a great result and is less of a pain than bonding plastic sidewalls onto your already profiled core. Granted, a lot of things become easier when you get a robot to do the work for you!