Can't go wrong with the S&W LE. Got the best pieces ever in it. Coming from a current soldier, I would recommend it to anyone its the closest thing to my issued m4 I could find. Barrel length don't really matter for home defense. People here the charging handle get pulled and get scared.

My true advice is get a flat top with popup flick iron sights. I never use my iron sights I got a red dot and love mine. Its for quick draws and shoot on the fly, great for cqc. One the battery dies in it you can flip the sights up look right down the aimpoint and still keep shooting. If you want the scope for hunting I would look into getting a Acog. They are very expensive around 1400$ but they are GI proof and don't have to worry about it breaking etc... Same with the m68 aimpoint if you have any questions let me know I'll help any way I can.