rowdy',
This is the only part of your question that I know anything about. If you have the regulator for larger tanks (a CGA 540 regulator), it will fit on any industrial (welding) oxygen tank, and of course your mask will still connect fine to your regulator. Smaller medical tanks use a regulator (CGA 870) that won't fit on any industrial tank. I don't know how to insert images here, so this is a link to what a CGA 540 medical oxygen regulator looks like: https://www.amazon.com/CGA-540-Style-Oxygen-Regulator/dp/B006GERK0M in contrast to the CGA 870: https://www.amazon.com/Medline-HCS8715M-Oxygen-Regulator-Connection/dp/B00KG8DNKU/ref=sr_1_fkmr0_3?s=industrial&ie=UTF8&qid=1535422718&sr=1-3-fkmr0&keywords=cga+860+oxygen+regulator