I'm ambivalent of 9mm revolvers due to problems with binding cylinders due to the tapered 9mm case backing out and jamming against the recoil shield. Others have had no problem with their versions. If you have one that works fine, 9mm makes the most sense, but you'll likely make a safer call by going .38sp/.357mag.
...Then I found a place it's dark and it's rotted
it's a cool, sweet kinda-place where the copters won't spot it.