I'd suggest getting a snap on/off OWB. You get the ease of the paddle but the added security of a belt holster.
Some good examples are:
Galco M7X Matrix
Galco also has several paddles available for the PM9, but I think you'd be better served with a belt mounted rig.
Regarding the Fobus roto, they are junk. I had one, I know. It was my first holster, I bought a Galco within 48hours of using the Fobus. Last week at the IDPA match, someone drew from a paddle of unknown make/model, and it came out with the gun, this can happen with paddles if they are not sercurely/properly mounted.
As for the adjustable holsters. I've found that in general people are better off with a holster that is NOT adjustable, find out where it rides best and leave it alone. The PM9 is relatively small, unless you are a small person, you don't need that much cant to hide it anywhere along the belt line.