I dont have anywhere near a full collection or assortment of cap and ball revolvers. If I did in order or prference:
1. I had a Walker and let it go. I currently have a 3rd model Dragoon. The Dragoon is a much better gun, the Walker has a tad more wow factor. The Dragoon is a great gun regardless of its antique classification.
2a, 2b. I do not have an 1858 Remington but I do have the Ruger Old Army in stainless. I think you should have both of these. I plan to have both.
3. I had a 36 navy and it was ok and fun for a lighter gun, but; it became to loose and beyond repair. That was my abuse and the gun was of poor quality. The 36 is an anemic caliber. If I were to replace it, I would like to try an 1860, which is a more attractive and more practical 44. I dont like the brass anything. Even a steel frame,open top can shoot loose. And I shot mine. That was at that time in my life when I was not old enough to buy a modern handgun, so these say a lot more use than most would today. Bottom line, IMHO, the 1860 is best in class, like the Dragoon.
4. I like to try the Lemat for cool points even though all reports on the reproductions indicate some issues. If I already had one, my opinion might be different.
That is it, 2 open top colts, 2 Remington style and Lemat just for cool.
If I had those 5, I would be a happy camper and look to expand into modern handguns or more diverse older repro handguns, like a Wheellock (my kit on order) or a flintlock or a caplock Pedersoli Howdah. The 20ga Howdah is way cool and serious power if you can deal with it.