Favorite powder is the one that works, and the one's mentioned all work really well as several have reported, so with the .357 maxi, it seems to be very forgiving, so just pick one, work up a load that your gun likes, and have fun!
Now that said, I'll get off topic a little.
You are right CW! It feels good to have those orphaned barrels and receivers of mine finally dedicated to their own.
I've got three Handi's that are put together without any one being an original rifle, and they all shoot great.
Still have one barrel that needs a mate though!