Roberto, welcome to the forum. All 3 revolvers that you have narrowed your search down are all great guns. Since you have indicated that they must be 2 1/2 inch barrels, I would assume you want one that can be used for concealed carry. The 66 or 19 are both k frame and a little smaller than the L frame 686. The 66 and 686 are both stainless while the 19 can be blue or nickel.

I have the Mod 66 2 1/2" and it is a very nice gun. For your shooting needs in both 38spl and 357mag, since you said your shooting would be 158g 357s, the 66 will be a good choice. If you want a larger gun the 686 is a more stout version and can handle more powerful 357 mags.