whether you select an inline or more traditional gun depends a little more on what you wish to do. A well tuned flinter will go off every bit as reliably as an in-line except for hunting during hurricanes. Except for some dampness considerations, a traditional sidelock can do everything an in-line can do. The care and feeding of an in-line is generally more costly than a more traditional gun. Shooting at long range, is a factor of what rifling the gun has, NOT the type of ignition. In the 1870's the Irish National Team were quite good shots at 1,000 yds with side lock percussion guns.
An in line's use for hunting is limited both in PA and elsewhere. A flintlock of proper caliber can be used in any PA big game season. The same cannot be said for the in-line.
In-lines are generally not "plinking guns" too costly to feed. A percussion or sidelock can be quite reasonable to shoot for such purposes. I can load my flintlock long rifle with 20 grains of black powder or 100 grains or anywhere in between depending on what I want to do with it. In-lines aren't generally as flexible in their loading.
There is little difference between a single shot centerfire rifle and an in-line. It would be a shame to purchase an in-line and then discover that you really want a flint gun.
I am glad you are wanting a muzzleloader, Several poster's here started with in-lines and then fell victim to the black powder world.