I liked the Galco SOB for my H&K P7PSP when I used to carry one. Avoid Kydex, as the finish on the P7 is not really on friendly terms with Kydex holsters. The P7 is kind of a weird case because the "holstered" part of the gun is very slim and narrow, while the whole bulk of the gun sits in the grip area. For that reason, I found that open-topped IWB holsters don't work too well with the P7.
Look at the Galco SOB, or any good quality leather or nylon rig with a retention strap.
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"Good people do not need laws to tell them to act responsibly, while bad people will find a way around the laws."
- Plato (427-347 B.C.)