I assume that you want a modern inline b/c of scope option...
There are quite a few options out there, do you hunt in areas that do not allow sabots? Like Colorado?
If you are unrestricted and don't want a switch barrel IMO I would go with an encore fixed barrel or tc triumph.
I have very good results with sabots out of mine, but beware it won't shoot a conical - power belt, hornady, maxi ball worth a crap.
Maybe the twist is too fast... Mine is good to hunt at 200yards, no hesitation. Last years buck was 191 yards. Using blackhorn 209, hornady xtp pistol bullets, harvester sabots, remmington sps primers it will clover leaf at 75 yards.
Aside from accuracy, the difference between most is the ease of cleaning. If you shoot sabots with 209 primers do yourself a favor and use blackhorn 209.
Another interesting option is the savage smokeless powder muzzleloader...but I have no experience with them.