Hi David. A 441 clone would be a good choice for you since it covers a wide variety of applications and leather thickness. We have customers using ours for briefcases, belts, handbags, knife sheaths, quivers, holsters, saddles and more.
The main issue with using 1 machine for all applications though is the constant adjustment you'll have to make in order to go from sewing something thin to something heavier. This is why ideally it is best to have 1 machine such as a cylinder walking foot with 3/8" sewing capacity for sewing garment weight leather, bags, belts etc..., and then you can use the 441 clone for thicker applications such as knife sheaths, holsters etc...
Feel free to post any other questions you may have.
Ron