Uberti makes some decent SAA clones. Cimmaron sells a fine version at the lower end of the price scale, plan on spending a little money to have the internal parts cleaned up. Mine always got lots of comments from other shooters.
US Firearms makes an expensively finished version of this gun, but a LOT cheaper than a real Colt. Friends that have them REALLY like them.
Alternatively, look for an Old Model Blackhawk, making sure that (a) it has not been "converted", or (b) that the original parts are available. These can still be had at decent prices, but the pre-conversion parts are getting harder to find. Some shooters think these are the finest single action "packin' pistol" ever; coil springs, high quality steel, but as small as the Colt.
A third choice: look for older single actions, such as the Virginia Dragoon, or JP Sauer and Sons-made Hawes Western Marshall. My 6" .357 Hawes is as big as a Ruger Blackhawk or Vaquero, but uses a Colt SAA, sized grip frame.
Finally, consider the Colt New Frontier. These are significantly cheaper than the SAA model, but are gaining value, and, naturally, are genuine Colts, but with adjustable sights. These are nothing like the Colt Cowboy, I might add. Pretty guns, accurate, no filing on the sights, and worth more when you sell it, if you've taken care of it. Mine is an early 3rd Gen NF, 7.5" .45 Colt.