9mm concealed carry
I tend towards compacts and full-size handguns for concealed carry, so I'd vote for the Glock 19 and Hk P7M13. I've carried both during in IWB holsters in the hot summers in Houston. Though I've never carried one, I have friends who also swear by the Hi-Power. Depending on the flexibility of your agency's weapons policy, either the Glock or Hk may be approved for a duty weapon.
For subcompacts, I'd go with a Kahr K9 Elite or Glock 26. Despite its weight, the Kahr's slimmer profile would make it much easier to carry in shorts, t-shirt, and a good "tuckable" holster. I'd try it with a pager pal and thunderwear also.
Though not a 9mm, for deeper concealed carry, I'd suggest the NAA Guardian .380 or Keltec P32 in a pager pal. You can carry these handguns literally around the clock in plain clothes and switch to a vest holster if/when you're in uniform.