you would put a few drops into the propane adapter before filling, ASg mags are as good to use as TM ones, just the lips are weaker, i run both, modded the tm ones to run propane no problems on either
if you want to mod them yourself, one one side you will see 3 pins, use a 2.5mm drill to a depth of 5mm, 5mm from rear pin prise out plug, seal the over pressure plug, seal around seal and refit
if you want a holster there are a few generic ones on the bay of e, which are not too bad, ive got one been using for last 6 years, still going strong
or if you want something a bit fancier on a large not so friendly forum, there is a bloke who makes them to order