When setting up a Home Defense AR-15 buy the best. Period. A Home Defense AR-15 has to perform, it cannot fail. So your Home Defense AR-15 must use the best. In short I recommend an Aimpoint T1/T2 with a weapon light (Inforce WML, Streamlight ProTac Rail Mount 1/2, SureFire Scout, etc.). For your Home Defense AR-15 picking a certain stock, grip, rail is not important. Identifying and laying down the authority is important. I hope this helped you in setting up your Home Defense AR-15.