See my Sticky post, "Proper Use of a Cap and Ball Revolver" at the beginning of this section.
It will answer many questions and guide you.
The last Traditions cap and ball revolver (an 1860 Colt Army) I purchased was made by Pietta. It was very well made, though still not quite as good as an Uberti. Still, for the money, it was a value.
The Ubertis are generally very well made, with an occasional dog slipping out of the factory. Ubertis have slightly deeper rifling, which tends to shrug off fouling longer than the other makes and their shallower rifling.
The deeper rifling can keep them shooting longer, and more accurately.
I do not suggest you buy a brass-framed revolver, for a number of reasons:
1. Brass-framed revolvers cannot shrug off the full loads that their steel-framed brethren can. Often, the brass gets pounded by the rear of the cylinder and the frame stretches or warps.
2. On the Colt designs, the steel cylinder pin screwed into the brass frame will loosen as the steel wears against the brass.
3. In my experience, brass-framed revolvers are not made as well as steel-framed guns. Their fitting is not as close and their final polishing is inferior. There are exceptions, and I've seen a few very nicely made brass-framed guns. But on the whole, brass-framed guns are cheaper than their steel counterpart because less time is invested in their manufacture.
4. Brass-framed revolvers require lighter charges to avoid wear and damage. This really isn't a problem for most shooters, since you don't need full charges to punch holes in cans or paper. Many people have brass-framed revolvers that they load down and have enjoyed them for years. Me, I like to use an occasional full charge just to get a feel for what the old-timers carried.
5. Brass-framed guns cannot use Hodgdon 777 powder. Hodgdon warns against using this propellant in brass-framed guns. It's powerful stuff. Frankly, the best propellant you'll find remains FFFG black powder. It may be difficult to find, but it's worth the chase.
The Confederates made brass-framed revolvers because they lacked the steel and foundries to make steel-framed revolvers. It was a last-ditch effort. If they could have made steel-framed revolvers instead, they would have.
If your heart is set on a Spiller & Burr brass-framed revolver, then happily get it.
But if you just want a good cap and ball, get an Uberti-made Remington 1858 in .44 caliber and use .454 or .457 balls in it. The stainless steel version is very forgiving about cleanup, so it's a good starter gun for the beginner.
My own Uberti-made Remington will put six .454 inch balls into a 1-1/2 inch circle at 25 yards from a benchrest. None of my other cap and balls will do that, though they come close.
If you can afford it, spend the extra money and buy quality. It will pay in the long run.