Red, everyone has to start somewhere, and "builder" or not, you have caught the powder smoke in your nostrils and are following it.
OK, your first build is a Kibler kit. Jim and his wife have found a niche that they can supply, and they do a darn good job of it. Never held a chisel against some beautiful wood and started it moving? Well, if you haven't, you've sure picked a great place to start. You may find that making a longrifle ain't your cup of tea, but you've acquired a jim-dandy rifle gun! With very limited experience, you have created a minor miracle, and bow your head to no man when you go to the range.
OK, so you really don't feel that building or assembling a period muzzle-loader is for you. That is OK, because there are a lot of guys out there like Mike Brooks. He makes a LOT of ML's for people who can't make them, and really turns out a quality product. And the same can be said for others like him - Mitch Yates, Richard Price, of St. Louis fame. And many, many others. After the kit from Jim Kibler, you will have a great idea of what makes a good longrifle, what goes into it, what makes it better or worse than the originals from the 18th and 19th centuries.
Chances are, however, that you will catch the bug that has infected more of us than even COVID did. And you may try another kit or two from Pecatonica, MLBS, TOTW, etc. And before too long, you will have acquired the skill (and tools) to make one from a plank, and what hardware to use for the particular longrifle that you really like.
You don't catch a fish until you drop the hook into the water, and, Redriver, I do believe that you are already caught. Enjoy the ride!