I'm not a real fan of any CVA rifle. I've owned a few, an build quality on these is pretty low. I opted for a Thompson Center Contender G2 in .45x209. the TC and others like it will set you back a bit more money, but they are high quality rifles. I do like a totally enclosed action: It rains and snows here, and having the primer totally enclosed makes it weather proof. Its a big deal here.
Powder: I've used em all. I happen to like Triple Seven. It does leave a crud ring in the throat area of the rifle. I do find that I can get best accuracy if I fire a fouling shot, swab once, and then load for hunting. I carry a cleaning jag installed on the loading rod. When I fire, I simply slap a flannel patch on my tongue, get it moderately wet, swab the bore once, then load. Accuracy is better that way, at least for my gun. Pellets are convenient but an expensive way to shoot. If you use pyrodex pellets, note that they usually have a darker end. This is a black powder "booster'. It goes towards the breech end. (I haven't used Pyrodex pellets in a decade. Not sure if they still have this).
Bullets: I'm not a fan of any sabot system that uses a JHP pistol bullet. They are not great performers. I d like sabots that use designed-for-muzzleloader bullet like the TC Shockwave, or the Hornady SST ML bullets. I am currently using Dead Center bullets I got at Cabelas, and I love them. I don't think they still carry them.
Do not go searching for highest velocities. These front loaders are not .270's. A ML bullet doesn't need to be fast. It kills with momentum gained from BIG bullets. I've used a 240 all lead bullet, .50 cal, loaded it over 70 grains BP out of a little short barreled 20" carbine. It plows clear through deer, even though its SLOW. Think about it - the old .45-70 has a reputation for anchoring animals, and it uses a big fat 405 grain bullet over a 70 grains of BP,and its considered a great buffalo and big bear rifle. It does not need speed. Ditto for BP. You don't need 150 grains of powder for max velocities and a light weight bullet. This works for .243's and 7mm-08's, but BP rifles used bullet mass instead of bullet speed.
If you want the ultimate in 'clean', savage makes (or made) the model 10ML. It uses regular smokeless powder reloaders use for loading rifle cartridges. Otherwise all the others are still "must clean tonight' kinda propellants.