In the world of Muzzle loading you can buy originals, you can buy store bought out of the box, or you can buy Contemporary Custom.
Out of the off the shelf ..Parker Hale UK, Hatfield and Green River Rifle Works have become lets say very desirable and are now collectable.
There is a strong secondary market for the Contemporary Customs, where some of the better known makers work can get very expensive rivaling the originals. In this market it is not all about how fancy the work is but the quality of the build.
Contemporary Makers: 2020
If you are a casual shooter stick with out of da box..unless you can stumble over something good for cheap.