An lp 14 would be my choice, especially if you are going to fill it yourself. the advantage of lp is that you can get a few more fills without boosting. On my rec rig I use a "Quick draw bracket" that attaches to the BC strap. On my twins I use a "pony tamer" system. on both I set the bottle inverted in case I need too shut it down for any reason. I've never had an issue with either of these setups and they hold the pony secure so as not too become a hassle. That's just my preference.