Second the Security Six, wish I still had the one I foolishly let get away some years ago. Fine gun. If you plan to practice mostly with .38 Special and fewer .357 loads, there are good Smith 19's to be had pretty reasonably, and they are great revolvers--I love K-frames. Used 586's are available too, but they seem to be fewer and more expensive from what I'm hearing.
"Don't let macho be your epitaph."