I've saved up some money and I'm looking to get my first gun: a Benelli M4. As I've been reading up on it, I've gotten confused as there seems to be different models of it, some don't have interchangeable chokes, etc. At the very least, I know I want a pistol grip, the collapsible stock, and the 7 round magazine tube, but I've read that other parts should be replaced as well.
Would anyone be willing to give me a simple 101 on the Benelli M4? What parts can and should be replaced, where to p