I've resisted getting in on this thread, but must be having a benevolent moment. Jim Kibler touched on the answer to your question, in his gentle way.
Although there are cross over's near the middle of the spectrum, there are two kinds of folks, as I see it. There are those who study as much as they can (on their own) from various quantities of reference originals or literature, and then have at it, come what may. And there are those who just want to talk about it. This web site is a wonderful resource, with builders offering their work for perusal, critique and discussion, and offering advice when it is asked for. But you'll notice perhaps that some of them have not weighed in on this discussion, because it's an unanswerable question.
Wade, the advice you've received here is to study what you can, and then dig in to a build. I want to build my first Southern Mountain rifle too, having seen and handled several of Ken Guy's rifles, and studied both contemporary and original rifles in picture form on this site and Contemporary blogspot, and also the CLA forum. But still wanting more, I bought Jerry Noble's four book set, and poured over them for hours and hours. What I've learned from this is that there are almost no wrong answers. These rifles varied so much that you'd be hard pressed to build one that was not correct. Some of you are now thinking - what a pile of bunk! Of course there are nuances and regional features that are correct on one rifle and not on another. But unless you commit chisel and rasp to wood, you'll never get any closer than you are right now.
Good luck with your quest - perhaps as illusive as the Grail.