I am going to be setting up a pony/additional gas bottle. I have a 30 cu ft catalina tank to which I will attach a complete reg setup with a long hose and spg. I am looking to either buy or make a harness that would clip to the d-rings on my BCD. Similar to a sidemount system. I want to keep it readily accessible and easy to hand off if need be. Anyone know if or where they are sold or a do it yourself site? Thanks