Wow. I've had my TH9c for several months and only have about 400 rounds through it. In my defense, I've been quite ill.
I normally carry in an Allen belt slide holster I got from Academy just because it was cheap and thought I'd try it with my Ruger KP90DC. Well, it fits about anything in that general frame size including the TH9c and even my medium and small frame revolvers. I just leave it on my belt and I can put a .22 in it when I go out back or carry about anything without changing holsters. It covers the trigger well and has good retention.
I also found my Fobus paddle holster I got at academy that fits my PT145 also fits the TH9c. I just had to tighten the adjustment a bit.