You might consider getting an oxygen concentrator as well. They aren't cheap, but you don't need a regulator or flashback arrestor, and you can go for years without ever needing a refill. Believe me, they pay for themselves over time, and refurbished is just as good as brand-new for glassworking. and cheaper. A good site to start looking is
https://www.oxygenplusmedical.com. Good luck!