Scott- Make sure you are tracking all the Colorado muzzleloader rules! The states out west tend to be very particular on what they will allow.
Colorado for example: DOES NOT allow
pelletized powder or
sabot projectiles and DOES NOT allow for scopes or any battery powered device to be on the rifle.
I would highly recommend spending the $30 to get a Blackhorn 209 breech plug and then use BH209 as your powder. It is the cleanest and most consistent available and you will want to eek out every bit of performance that you can with a muzzleloader.
As for bullets- since you cannot use sabot projectiles it limits your choices significantly. But Thor, Hornady FPB and Powerbelts are going to be your options. I've found muzzleloaders (esp the several CVA in-lines) to be finicky with charge and projectile combo. BUT, when you find the right one they are capable of great accuracy.
I would also start taking a look at premium iron sights. A good set will extended your honest effective range. Iron sights are not a gimme proposition, even with an elk. Moreso- especially with an elk where you aren't likely to get a follow up shot so the first one needs to count. Here's a great read on options and how-to.
https://www.gohunt.com/read/skills/increased-accuracy-from-an-open-sight-muzzleloader#gs.xriZoC0