Why doesn't Bushmaster offer the 20" A2 government profile barrel in a complete upper instead of just barrel only? Secondly on you web site the standard Phantom FH has an option when adding it to your cart to select install permanently if you are purchasing a 14.5" upper or barrel. However the new Phantom FH/Compensator doesn't have such an option. Is there a reason for this? I would like to order a 14.4" M4 with one permanently installed but prefer to do it via web rather than calling it in when the ban dies.