If I go the SIRT route, do I need a gun specific model? Do they make various models? The only thing I've found in a quick Google search is based on the Glock 17. One of the things I'm going to need to incorporate in my training is the thumb safety. That needs to be part of my draw. I'm afraid that otherwise, I may one day have a very good sight picture on the guy who kills me while I jerk on a safed trigger.