Traditions makes a Kentucky caplock rifle that is an accurate shooter.
What's really good about it is that it's a .50 caliber rifle instead of .45.
Their model doesn't have a lot of frills but it's a good basic Kentucky rifle.
http://possibleshop.com/rifle-kentucky.html
Unless you'd prefer the fancier Traditions Shenandoah .50 with double set triggers and a brass patchbox. I've shouldered one and it's a very comfortable rifle.
http://www.cainsoutdoor.com/shop/product.asp