RE: 9mm revolver
I'm aware of the capabilites of high pressure 9mm's as I've used them for to take coyotes for the last 5yrs (handloads) out of a hi-point carbine, however, when's the last time you found +P+ ammo on the shelf? I've bought under a dozen boxes of +P ammo, and I bought most of them all at once. Granted reloading them is as easy as standard pressure ammo, but not everybody reloads, this guy doesn't seem like the type that does.
As far as just finding stuff easily, the .38spcl wins the ticket.