If you give Troy Roope,at Stonewall Creek Outfitters a call he has a lot of precarves in stock, and he builds, and teaches. both early 1800-1820, and later 1820 -on. They are good starters, and Troy has good prices, and can help you with what you will need. You will want an English lock, and most everyone agrees that the Chambers late Ketland is the lock of choice. It can be customized, and most of the named builders do. The precarve will give you a starting profile for an eastern Tennessee rifle, the you just need to study some of the makers, Bull, Bean, and the Beals are among the most copied. Jerry Noble's books are a great resource for makers and their guns. research the Contemporary makers Blog for Ken Guy, Keith Lisle, Ian Pratt, Southern Mountain, or Tennessee. Oh yeah Troys number is (434)993-3557. Also you can get parts from Track, Pecatonica, or MBS, but I think you will get better service as a beginner from Troy. My two cents.
Bill