I'm not sure if you'll be able to find a place that just sells the aileron cores. In the second edition of the plans I believe they were incorporate into the wind construction and were cut out after the wings was glassed.
In my opinion, foam cutting isn't as bad as some people make it out to be. I'm not a craftsman by any stretch of the imagination but I've been able to cut some reasonably accurate foam cores. If you can find an early Canard Pusher where the ailerons were added to the Varieze, it has the template to build the aileron separately. As for a hotwire saw, find a local RC modelers group. The modelers typically have some really nice saws that make it easier to cut good cores. Give it a try, the foam's cheap and you might be pleasantly surprised by your results. If that doesn't work out, let me know.
Ben
