why not use an off the shelf shotgun or rifle stock and jut modify it. that would leave you with a lot of options and usually they can be picked up fairly cheap. Take a look at someone like midwayusa or brownells. both sell replacement wood. might also be worth contacting a custom stock maker like boyds gun stocks and see if thy can do a custom stock for you that you just have to attach. might end up less expensive and you will have less time into it.
either way seeing your work is always a pleasure. thank you for taking the time to bring us along on your journey.