I have a CVA Accura V2 and really like it. If you're going to shoot much it helps to get a second breech plug. They aren't super expensive and it saves time cleaning at the range if you can clean two at a time with more shots between.
Definitely get a "range rod" too. The rod that comes with most muzzleloaders is meant for field use, not firing dozens of shots in one day. Many bend or break easily, especially where the threaded ends are for accessories. I have a spin-jag on mine and I'm not sure it's really THAT big of a deal but it seems to help loading a bit.
I upgraded the sights on mine, I can't recall the brand name (it was a few years ago) but I'm sure others here will chime in. But it's a "peep" style which is legal in CO (this style has no glass in it hence no magnification). Paired with a better front, it really helps a lot.
I know a lot of folks sneer at B.O.R. Lock's but I like them a lot. They're super easy to load, and they're legal in CO - specifically named in the big game brochure. I shoot a 50cal Federal 270gr copper and it performs great at the ranges I can shoot at anyway. (I'm no sniper.)
You probably know this already but you have to use loose powder, not pellets. Everyone has a different system for this but to save weight I don't use a brass powder horn. I actually use test tubes that I preload before a range day or hunt trip. I use mini corks for the end stoppers rather than plastic caps. I don't dump them on the ground on purpose, but if I lose one in the heat of the moment I don't have to worry about it.