Who is "they"? A lot more manufactures out there than just S&W. And even if there is not one exactly like you want, I bet there are several that start off closer than the Sport.

I get it, you like to play with yours like it is a Lego set. Nothing wrong with that. I like the simplicity and no frills of the Sport. Nothing wrong with that either. Mine is a Sport I as well, so I don't even have an ejection port cover or forward assist. Just don't feel compelled to change a thing on that rifle.