So I'm going to start assembling parts for a new AR15 pistol build. I have an Aero Betsy Ross lower and a 12.5" Carbine gas system Ballistic advantage barrel. I am wanting to use the SBA3 brace and a Dead Air flash hider. So whats the best adjustable gas block? Is there a rail I can tuck part of a Sandman k in? Its 1.5" in dis. Trigger will be a ALG ACT.