First of all, I'm not the builder for you. I'm the type of builder you're talking about. I produce three to four guns per year, mostly iron mounted southern guns. I build from a blank, and make my own iron hardware and double set triggers. I don't have a waiting list; but for personal reasons, I'm not accepting new work for at least nine months. I'm currently on rifle number 12 from a blank; and I've bee shooting flintlocks for about 38 years. So I do have some opinions and advice.
I love the .58, and have been shooting one for almost thirty years. With moderate charges (I shoot 70 grs. 3f in my .58) it's a real thumper on game. I don't hunt elk these days, but the .58 would be my choice. It goes without saying that it's great for deer as well, but I prefer my .50 Southern Mtn Rifle for deer.
Since you've never shot a flintlock, I would recommend shooting flintlocks... plural... before making a decision. Don't just shoot them, but load them and clean them too. And shooting a squirrel gun is not like shooting a big bore. They're not that different; but there is more fuss and boom... and it can be intimidating to a new shooter... resulting in a nasty flinch that can dampen your enthusiasm.
You want an iron mounted gun. Is there a specific reason you want iron? By far, most of the guns produced were mounted in brass; so iron limits the type of gun that's appropriate. And, while there is plenty of iron hardware available, it doesn't mean that it's appropriate on any style of gun. And yes, a builder could build whatever you want... but a good builder isn't going to put their name on just anything.
You want good grain, not a plain Jane, and a great builder. For $2500? The market seems pretty soft right now, but a fair price for good work will cost you more than that for a custom gun built from a blank. There are some people out there who assemble guns from kits and pre-carves, and you could have someone assemble something for you for that price i imagine. There are some high quality kits out there that can turn out to be great guns.
It also depends on what you want in a gun; and what you want that gun to mean to you. I'm a reenactor; and I have ancestors on both sides of my family who were settlers, frontiersmen, and pioneers. I'm pretty sure that my ancestors, and the mountain men I emulate, did not carry guns that were made by robots. A custom gun requires hundreds of measurements, thousands of decisions, and thousands of passes with chisels, rasps, and files. Therein lies the beauty of a well built custom gun. But a person should expect to pay a fair price for that.
Having said that, I wouldn't recommend a custom gun for someone in your situation. It's a big investment when you really don't know yet, whether you're going to be hard core flintlock shooter; and where the sport will take you. I would recommend a high quality used gun, or something assembled from a high quality kit.
Your description leaves me the impression that you may not know what type/style of gun you want. If so... do what it takes to figure that one out before you spend any money on a gun, and risk ending up with something you're not happy with... and that you'll take a loss on.
Spend some more time seeing what's out there... what catches your eye. Shoot some guns. And don't rule out brass, iron, and all of your options so soon in the game. Don't make any quick decisions. My two cents.
