I've been interested in doing F&I War and American Revolution reenacting and have been studying muskets of the period. A good place to start is here:
http://www.trackofthewolf.com/
They are expensive, but you will not find junk here. High quality and beautiful products. They also sell kits to build your own.
You can also look here (from Canada)-
http://www.militaryheritage.com/
...and here (in USA)-
http://www.veteranarms.com/Reproduct...-Arms-LLC.html
Dixie Gun Works also sell Kentucky rifle reproductions -
http://www.dixiegunworks.com/advance...tucky&x=12&y=7