I just picked up my 3rd Benelli M1S90 this morning (that makes 2 tacticals and 1 field), it has a +2 mag tube extension which makes it 5+1. My other M1S90 has a +3 Benelli extension on it. I would like to put a +3 on the one I just got. Who makes the best tubes out there? It needs to have the integral sling mount like the stock one.