If you want an open top Colt, and since you already have .44 caliber, I'd suggest the 1860. It was the most modern design that Colt put out, before the cartridge guns.
Folks will take me to task on this, stating that the 1861 in .36 caliber was the most advanced, but it's really a non-issue. Both are identical designs, just different calibers.
The 1860 is an accurate shooter, contrary to what many claim about the Colts and their wedge system. If the wedge is in tight, the Colt will shoot accurately, all other things being equal.
I have a Pietta-made Colt 1860 that will put six .454" diameter balls into 2 inches at 25 yards from a benchrest. My Uberti-made Remington with fixed sights will equal that, and occasionally better it.
But I have no doubt that the Colt is the Remington's equal in accuracy. It's just that my 57-year-old eyes don't deal as well with those rudimentary Colt sights.
If you want a .44, get the 1860.
For .36 caliber, I suggest the 1861. It has the same balance as the 1851, but a much better loading lever and greater clearance under the rammer for loading coincal bullets, if you desire.
The 1861 is an improved 1851.
Buy an Uberti. The rifling is deeper than Pietta. This helps to shrug off fouling in the barrel and may aid accuracy. My Ubertis tend to be slightly more accurate than my Piettas, in my experience.
Sounds like you have some pondering and deciding to do ...
"And lo, did I see an ugly cat. Smoke. Brimstone. Holes in parchment. And this ugly cat was much amused." --- The Prophesies of Gatodamus (1503 - 1566)