I'm planning on purchasing a M&P Compact 9mm 2.0 and am trying to make a decision between the 3.6in barrel and 4in barrel. I've always carried a 3.1in shield and am unsure of which of these larger models to pick. Please consider my following questions/statements in your response and thank you for the advice!

1. Accuracy: I want to be able to comfortably make long range shots (25yds + in a Church defense situation). I'm guessing most people would say .4in won't make much of a difference when considering sight radius, but full size handguns are generally considered to be much easier to shoot accurately at longer ranges and the full size M&P is just 1.25in longer than the shield.

2. Thoughts on OWB or IWB? I am a thin and short guy (5ft7) . I do like to wear flannel shirts or leather jacket frequently. During the summer I'm not sure if I'd be able to get away with the compact under just a t-shirt but that's mostly a width/height of the grip concern, not overall length.

3. Accessories: Any weight to the idea that there might be more lights, red dot sights, etc., available for a 4in version over the 3.6in version? How easy would it be to try and get a threaded 3.6in barrel over a 4in barrel for secondary home defense purposes with a suppressor?