For ease of cleaning, and the ability to change out cylinders for reload, I would suggest going with a 1858 Remington style revolver.
Get one in stainless, to reduce the chance of rust.
R&D and Kirst make 45colt drop in conversions to give your gun more versatility.
Load your powder, ad a wonder wad, and seat your ball then cap off the chamber with a dollop of bore butter/wonderlube 1000+.
Cap wise, CCI caps are good and hot, and magnum caps will help with ignition should the powder be a little damp.
I dont oil my C&B revolvers. instead I coat them in bore butter/wonderlube 1000+. It prevents the rust, and keeps fouling from becomming an issue.
I bought a Remmie from a lady who's deceased husband kept it in the house for protection. The gun was loaded when I bought it, and had been loaded for 5 years prior to me getting it. When I took it to the range, all chambers fired, even after having been loaded 5 years ago.
Avoid synthetic powders that are hydrostatic, as they will attract moisture.
You may find that 30gr 44cal pyrodex pellets will fit your needs. Makes loading a snap, and eliminates the need for a powder flask. My gun loves em!