I've killed a lot of elk muzzleloader hunting. I have a Remington genesis which is no longer made, but any of the new models out there are good to go. Best thing is to hit the range, figure out your bullet/powder combination and stick with it. Something out to 200 yards is all you need. With the right bullet and powder you can be within 4 inches at 200 yards with open sights pretty easily on a bench. Then practice shooting from logs or tree limbs, or carry a monopod so you can be comfortable.
keep your powder dry and you will be fine with any of the modern in lines.