Sorry it took so long , but thank you very much.I believe you can get them from KelTecs website
Kel-Tec CNC - PF-9 Accessories - PF-9 +1 Grip Extension
I never leave home without my P3AT. It kicks like a mule and is only acurate to ten yards, but that is far enough. As to the kicking, thats why you should practice with your EDC. With the factory 9 rnd mags for the P3AT I can get a better grip and is much easier to control. Also purchased direct from KelTec