As others said, it is hard to give a recommendation. You stated you want either scandium or aluminum, and you want a S&W. So, the rest is just what features you prefer. Do you want stainless or blued look (look because in scandium or aluminum, either finish will be equally protective, and neither look comes from stainless steel/raw metal or bluing)? Do you want an exposed hammer, shrouded hammer, or enclosed hammer?
Personally, I like all steel in a J-frame (and 6 rounds, so not a J-frame). I do have a 442 that I rarely carry (when I can carry) and almost never take to the range (it is not a fun shooter). I have an all steel Taurus 85CH (basically a bobbed hammer) which I do occasionally carry when I can and take to the range from time to time, it is much more comfortable to shoot. I have a Rossi 461 2" that I don't trust since it had some issues. For occasional pocket carry, and deeper concealment IWB, I'd get a Kimber K6s if I was doing it again.
Based on what you are looking for, I'd go with an aluminum version and not scandium. With that small/light a gun, I'd never want to shoot magnums, and the couple extra ounces will make practice with .38spl a little more pleasant. It should also be pretty substantially less expensive than the scandium .357s. Like I said, I have the 442. However, if you don't have a preference on features (stainless/blue, exposed hammer, hammer shroud, enclosed hammer), go with whatever you can get for the lowest price.