Kahr pistols can indeed be hit or miss. I've owned 4 of them, currently have a PM9. My PM9 will not work with the 7-rd mag...severe nose-down jams, even with FMJ-RN ammo (this was well after the break-in period). This is a known issue (check the Kahr Talk forum) - called Kahr, they replaced the 7-rd mag with a 6-rd one. That was their "fix."
Last week, I tried a 50-rd box of 147 gr Speer Gold Dot ammo through my PM9 - got two nose down jams, even with the 6-rd mag. Right now, I've got it loaded with a 124 gr +P EFMJ in the chamber, 3 PowRBalls in the top of the mag (for better feeding) and 3 EFMJ in the bottom of the mag. I've ordered more of the 124 gr +P EFMJ (haven't been able to find any in over 2 years) and will run a box trough the PM9 once I get it in to see if it feeds any better.
Depending on how that goes, I see 3 options. If it feeds the EFMJ, I will likely keep it and use that ammo. If not, I will try a few boxes of PowRBall, but I dislike that ammo because I consider it too light for caliber. Last option is give up on the PM9 (and Kahr) altogether and try to make a revolver work for pocket carry - Side Guard holsters (sponsor here) make pocket holsters with an anti-print panel for the LCR (leading contender). I might have to take my pants to a tailor to deepen the pockets, but I may do that just to gain the reliability of the revolver, if it comes to that.
Sorry to the Kahr fanboys, but I think the OP is wise to consider his options carefully. For the record, it seems the steel Kahr pistols are more reliable, from what I've read.
Good luck!