Both are fine designs.
The Colt is better balanced and points more naturally.
The Remington has a far better sight picture for target work. Its design is stronger than the Colt, but this point is moot because we're talking black powder pressures anyway.
And both designs are strong enough for the mild loads used in the cartridges employed by their conversion cylinders.
For the first-time .44 user, I'd suggest the Remington. The sight picture is better, so you'll be more accurate with it.
But I won't completely sell the Colt short; it too can be amazingly accurate if you keep the wedge in tight.
I have both designs, as well as an 1851 Navy, 1862 Colt, a Remington in .36 and a Remington .36 target model with modern, adjustable sights (sold by Navy Arms in 1973; a rare bird).
You may wish to look at the Remington in stainless steel; it's more forgiving if you get lazy about cleaning right away.
Colt made 2nd generation 1860 Army revolvers in the 1980s of stainless steel. I saw one, and a stainless steel 1851 Navy, in a gun shop in Tacoma, Wash. I couldn't afford it at the time.
How I wish I had thrown BOTH on plastic and paid the piper later!k
The Colt 2nd generations in stainless steel are rare critters, not often seen today.
After all my rambling, I have to agree with the others: get both. You won't be disappointed.
Just be sure you get steel-framed guns and not brass-framed guns. They're almost always better made than brass guns, and they can take the full loads that strain brass-framed guns.
Use .454 or .457 inch balls, real FFFG black powder, and a greased felt wad twixt ball and powder. The slightly larger ball, when rammed into the chamber, creates a wider bearing band for the rifling to grip, which may aid accuracy.
Read my sticky at the top concerning cap and ball revolvers. Tons of good info from me and others in that post. Print it out and refer to it often.
You'll be miles ahead of me in 1970, when I began shooting cap and ball revolvers and had almost no direction.