I've got one for my PM9. I like it. I first bought one for my KelTec 3AT and I liked it so much I got one for the PM9. Not sure of the size, just ordered off their website and selected the PM9 version from the drop down menu.
While it is a great holster, I do prefer to carry my 3AT much more because of the size/weight differential. It's just plain easier to pocket carry. But, with the right pockets, the PM9 is no problem once you get used to the weight. The holder itself holds up well and positions the pistol for a good draw. I'd recommend one.