I don't know what the "best" holster would be, but I'll throw you a few suggestions that I recently considered.
Galco makes several for that gun. See http://www.usgalco.com/HolsterPG2.asp
If you like plastic better than leather, Fobus might be of interest: http://www.fobusholster.com/catalog/Holsters-1-1.html
Here's what I just got for my PT111: http://www.highnoonholsters.com/Prod..._decision.html
The Crossbreed SuperTuck is another good one worth looking at: http://www.crossbreedholsters.com/beltslide.html
These certainly aren't all of them, but they might be something to chew on 'till you get some more suggestions. Good luck.