WSMITTY01 has a rifle that sounds similar to mine. Same relatively odd caliber, (53) I bought it from Track of the Wolf in an in-the-white kit and refinished it. I'm informed it's "the Sante Fe Rifle, with a Maple Stock that Track of the Wolf commissioned". I wasn't in a club or anything, but learned how to build it and shoot it by reading and trial and error.
My point in writing is to avoid my errors and frustrating experinces--it'll be more fun. I'd recommend a percussion, and join a club or hang around knowledgeable muzzle loader shooters as much as you can. It'll be worthwhile.
My experience with ML's includes frustrations and heartaches--because I didn't involve myself in clubs at the begining.
First I bought a Zouave replica (don't discount a military musket as a first ML); percussion. The caps I could buy locally didn't go off the first time you pulled the trigger. I didn't know another soul that had a ML in the area. That was in 1970.
Then, I bought one of the first Thompson Center Hawkin Rifles, in 50 cal. 1X48 twist percussion, a compromise twist. It came with a .490 mold, and I bought 1000 remington caps. Worked great. Fired everytime, and accurate. Boy, was I hooked. Wanted to use it deer hunting. However, I determined that if I loaded much past 70 grains of BP the groups started getting bigger. I wanted more power, or what I thought was power, and went to the 370 gr maxiball. 90 grain loads--I broke the stock.
I bought the Uberti kit from Track of the Wolf, and spent a winter putting it together. It's a beautiful rifle, still my pride and joy. But I couldn't make the blasted thing go off! I did everything I could think of, finally took to completely degreasing the barrel, false breach and nipple with new tet--degreasing fluid---then dribbiling 4FG under the nipple to make it go off. I actually shot a couple of deer with that combination although the members of my hunting group hated to see me take that ML out--we shared the deer and I wasn't pulling my weight. Fully 1/2 the time when I fired it it would go "POP" on a dead load.
Finally drove up to Track of the Wolf, and they talked me into some expensive caps, RWS, made in Germany. Ya right, there's a difference in caps; the remingtons sounded powerful to me, and they worked on the Thompson Center rifles. However, the simple expedient of having an experienced ML shooter trouble shoot the situation solved the problem. Now I just take the gun out of the safe, load it and go hunting. Haven't had a mis-fire since I went to the RWS cap and I leave the remingtons alone.
My point in all this is "join a group" even if you have to drive a ways. It will cut down on the frustrations, and even though they are still fun to work out, it takes a lot of time.
I'f I was going to get a traditional ML, I'd certainly look at the Lyman Great Plains or the Hunter. Watch out, though--they are different twists. I wouldn't hesitate to use the round ball but the 1/60-66 twist barrel will get more performance out of a round ball.
I've shot my last 5 deer and about 30 woodchucks with my .53, using a .525 ball 110 grains of FFG and the RWS cap. It shoots flat as a bow string to 100 yds, and gets full penetration on a deer--ball goes all the way through. The last doe jumped once and lay there at about 75 yards.
You will have a ball with a muzzle loader when you get all the details worked out. A flintlock COULD be fun, if you had access to people that could inform you how to get past the bugs. For a first rifle, the flintlock would probably have been even more complicated for me.