I'm assuming you plan to shoot Bullseye since you want to build a wad gun. If that is right, you would want to use a gunsmith that the bullseye community is familiar in case you ever want to sell it. They will snap it up if he is a good 'smith with a good reputation.
Phil
This is about as solid advise as you'll get.... pays in the highpower field too.
Of course I never sell guns, I only buy... but if you might ever, this is super advice.