Being that you have a longer 3" barrel revolver, it will do well with any ammo.
Both the 38 +P or the .357 ammo will work but as mentioned
the 38 is a lot nicer on the ears and eyes in a dark room condition.

If you get a chance to shoot in a dark place, see if you like either one....... but use ear protection each time, if possible.

Both have their place.