There is only one SAA on the market. Colt. Nobody else makes an SAA. USFA doesn't claim to make one, neither do any of the Italian outfits. Using SAA generically is an insult to Colt, though God only knows they've insulted themselves often enough over the past 30 years but that's not here nor there.
The best SA
revolvers are by Freedom Arms, period, no argument possible...well...'cept for maybe a full-on custom by a top Rugersmith like Hamilton Bowen
The best reproduction of the original Colts are the USFAs, again, far and away if you want an original look, original feel, original action. I would go so far as to say some are closer to the pre-WW2 Colt SAAs than the post-war Colts made on different machinery (because the 1st Gen tooling was literally left out in the rain during WW2).
Ruger has the best bang for the buck in anything "SAA-like". Not as authentic as some of the Italians in terms of the action type (and things like the particular steps in the reloading cycle - Rugers don't have a half-cock fr'instance).
Oddly enough, if you put a SuperBlackhawk lowered hammer on a Ruger New Vaquero it won't "look right" but the reach to the hammer will be closer to a 1st Gen Colt than a post-WW2 Colt SAA (2nd through 4th Gens). The Ruger New Vaquero's frame size and general feel is a near-clone of the post-war Colts. I've taken careful measurements comparing post-war Colts, pre-war Colts, a USFA Rodeo and my NewVaq357 with an SBH hammer mod. All put the hammer tip at the middle joint of my thumb EXCEPT for the post-WW2 Colts.
I believe that the lower hammer on the original Colts was one reason why strong-side thumb cocking was more popular back in the day than the off-hand-cocking seen among the SASS/CAS guys today when they're in a class that can shoot two hands on one gun. Bat Masterson specifically wrote about getting his thumb up on top of the hammer by the knuckle, which would have been more difficult with the high hammers that have dominated since production started back up in the 1950s.
The high hammers may have been influenced by Hollywood "fast draw" myths...