Some silly question on ozone therapy

Hi,
I have discovered some days ago the potential effects of ozone therapy and I've decided to buy an ozone generator.
I'll probably get an EXT 120 form Longevity.
I live in Italy and here, despite ozone therapy is legal, it is quite impossible to find "normal" peoples exchanging info on the subject; it seems to be something only for doctors, at any level and I think no one has an ozone generator in the house. I xcalled a doctor that uses ozone therapy to know what kind of treatment she gives, but she didn't want to say one word on the phone, like if it were a secret or illegal.
I've found the info on this site very precious, but there is one thing that is not clear to me about the oxygen used.
Are we talking of liquid oxygen? I see that the tanks I can buy on Longevity site are 240 and 640 liters, but they are very small, so I assume that liquid oxygen is put in the tank and the 640 liters are meant at room temperature, when the oxygen expands. Am I correct?
I am asking this because I have called an oxygen supplier and he said : what??! are you sure you can put 640 liters in a small tank? and when I said: I guess it's liquid oxygen, he told me that it sounds strange.
So, please, can some of you explain this to me?
Does any of you know if the connectors we use here in Europe are different from the ones used in Canada?
I am afraid I buy something that is not ready to be used.
Additionally, I would like to buy a potable steam sauna or, in alternative, a body suit to use after a hot shower to use ozone on the whole body, but I can't find anything on Ebay; can you please suggest some online shop?
I probably have other questions on the subject, but I don't want to furtherly bore you for the moment.
Excuse me, but here I feel like an ET.
Thank you
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