jmcbang....re 19 vs 586: I don't think you can go wrong with either. As stated above, the 586 has a bit more meat in the forcing cone, frame and cylinder walls. In the 2.5 and 3 in bbl guns, the weight difference is negligable. The grip frame is the same. In the 4" and longer bbls the 586's full length shroud makes it a bit more front heavy.........some like that and some don't.
With either one, stay away from ultra high pressure silhouette loads..........for that you need a N frame or better yet....a ruger.
For commercial defensive loads and under, either gun should run for many thousands of rounds before needing re-timing.
Ultra fast shooting (in the 6 per second range) will cause more wear n tear faster than defensive .357 loads. If you are into the fast n fancy stuff, the 19 should stay in time a little longer due to the slightly less cylinder mass if both have the same cylinder styles (ie both either recessed or not). The star, the hand, the hand pivot pin, the cylinder notches and the cylinder stop take a beating when crankin em out real fast.
I commend you on your choice of blued guns. In my opinion, based on experience, the blued versions will outlast their stainless sisters.
Sam