Hi #34548
You will have to do your own research on that one. I can't possibly know the local policies of oxygen companies. Most prefer to lease or sell you a tank so that when it comes time to replace it with a new one, they just exchange tanks. If you buy a shiny new one and want the same one back, it may take a long time to have it sent away to be filled and returned. It will also probably cost a lot more that way for the refill. I seldom recommend buying your own tank.
You will need to buy to your own regulator if you want to use it for ozone production. Oxygen companies generally do not stock pediatric oxygen regulators and this type of regulator is what you need to feed slow oxygen flow rates to an ozonator.
Hope this helps,
paul