I've used a Seidio Surface case for my blackberry and such in the past. Fairly happy with it.
I just got the Seidio Convert kit for my iPhone5. It includes the surface case, but also has a soft and a hard layer to go over it for when you are on duty. The clip is sided for duty belts and has a sliding lock.
You can add a 'Surface' clip for when you only want to use the smaller Surface case.