Hello! I've carried the P9 for probably a year and a half now. Fit's me like a glove too. Well, I agree with what the others said. As for thinness, nothing else compares unless you're talking a KelTec, etc., the grip is the issue. I've found it best to use an extreme cant with my holster. By doing so, the gun disappears. If the gun barrel is straight up and down, the butt of the grip will show as would any weapon. The PM versions took care of this by chopping off some of the grip. The pm is great for pocket carry but even with my small hands, it won't give me the grip of the P9.
The extreme cant of 20% works very very well. If you can imagine a vertical line, hold the pistol so the tip of the barrel touches the line and the butt so it just barely touches the line. That'll show you the cant you ideally need. Then, if you have a good holster, it's about as concealable as you can ever get. I love the trigger on mine. Its super smooth, the gun is accurate, and the recoil isn't too bad. Mine has the blackened slide and night sights. Both of these options raise the cost and I debated long and hard about getting them but I'm glad I did. The night sights are excellent day or night and I just like the looks of an all black weapon.
I think the Max Con V talked about on this site would be ideal if you can get the cant I talked about. I think if you talk to a custom maker they'll be able to accomodate you. I have a fist #3 kydex holster with a J hook. It's their version of an extreme cant but it's not as much as i would like, still it conceals very very well. The J hook makes it easy to slip on and take off and the kydex is very thin so I'm maintaining that thin profile that makes it so easy to conceal.
Now when I put my little S&W J frame revolver IWB, it feels like I put a chunk in my pants.
Good luck with your choices. I really do think the cant is everything....
God Bless
Gideon