Summer carry

[VietVet68]

With summer coming soon I think this is the year to buy a true pocket gun in 9MM unless I can find a .380 with a muzzle velocity that's acceptable. I know that the proper ammo is needed also so if anybody is aware of a good combo please let me know. I already own a Walther PPK/S in .380 but believe me, it's not even close to being a pocket gun.
So far I've been investigating the following:
Kahr PM9
Kahr CM9
Ruger LC9
Sig P290
Ruger SR9

The overall length of these is close to 5" max. and mags are either 6 or 7 rounds.

I've seen many more but when I see a gun selling for $150 I just have to close my eyes and keep going.
Are there any more candidates I should consider before I try to make a decision? the parameters I have are:
1. 9mm
2. Close to 5" overall length
3. 6-7 round mags with pinky extensions as an option.
4. Plastic frame and steel slide
5. No Glocks--they all look the same to me.
6. I'd like to keep the price below $650

Any suggestions?