As for getting all the right parts, I recommend digging through the museum here and the antique collecting section to learn of the various styles. Some you may find more to your liking than others. Also many times there's an earlier and later division of schools.
Once you get an idea of some styles/schools you prefer, then you can learn how available proper bits and pieces are for each. Of course the most commonly sought stuff will be more available and
economical-with multiple vendors. And some builds require a lot of work/sourcing to get proper parts-not that there's anything wrong with that, but it's usually a thing for an advanced builder and/or the desires of someone deep into the culture needing that "special" piece.
Some schools include more fancy work and are thereby less beginner friendly.
Caliber and architecture are involved as well. So mind that if you're set on or "need" a particular caliber for hunting. I really pushed that envelope, and my mentor frowned but let me do it. Today I would frown just the sane as he did then. But that "my" school has lots of rules breaking in it, so it's not completely off base.
Fancying one up (carving, inlays, engraving) can be outsourced if that the type you must have. Expect to pay by the hour and wait your turn for best results. Also, letting in the barrel (bbl) is often outsourced by makers both amateur and professional. For a swamped bbl, probably a great idea for your first-if that's what your build calls for.
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I was on a two-man crew in a three-man company. Mostly rural and suburban work. All mountain sides or swamps and sewers it seemed. City work was worrisome with the noise and traffic hazards. I don't miss outdoor work. Three of ten days were perfect, other seven were frigid or boiling. Learned a lot.
edit: Our closest encounter was when my partner unknowingly stepped OVER the biggest timber rattler I've ever been that close to (could have had a possum or cat in it's belly-fat and coiled looking not unlike a spare tire on the ground). We were in chest deep grass and I saw it as soon as he walked over it-and shouted at him, he turned to look and freaked a little. I made a different exit and went back for another pic--and it was gone and vamoose we did (shaken for the day). Finished that job in following weeks wearing sidearms and bite guards, there were other rattlers on it too. He walked past so many snakes-it's a wonder one never tagged him. Worked a hillside job where a panther was reported to be roaming. Saw no trace or sign.
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Back to the original subject, you can also use the popular kit suppliers catalogs to get an idea of what particular
genericified types of longrifles/smoothies look like BUT- only let that steer you into better study of those originals they "descended from". We don't want to copy a copy without knowing what "compromises" if any were made in the design. It's too easy to miss nuances and details that way. If you have a particular interest in a historic event or person, that might steer your schools selection (older guns were always present in later periods-but later guns don't quite
fit back into earlier periods). This means more to some folks than others. Experts will disagree too, so be ready for that. It's often good to look at both sides of any argument.
Final: Others might well tell you to just grab a stick of wood and put a barrel in and make up whatever you think looks good. Any first gun has plenty of mistakes and errors, but if the architecture is good and parts are right, from study and understanding, (as can easily be accomplished here with research and inquiry) you'll likely be much happier with it further down the road (than with a hodge-podge frankengun). You don't have to bench copy a piece, but you also likely don't want to put a nose where and ear goes.
Best of luck and studies.
