Is a thumb break a requirement for your place of employment?
If not, Fobus makes some very nice holsters. They are molded plastic, but don't have a thumb break. They have a passive resistance system. The one I have for my C9 is nice and tight; it holds the gun well. For the JHP.45, they have a set screw so you can adjust the tightness of the resistance.
I love my Fobus. I cannot expound enough on how excellent it is.