All you need is a provider for the tanks, you can buy the regulator you need off Amazon for under 30 bucks......
If you are looking for an O2 supplier to rent you a high flow reg, you will look a long time. Most of them don't even know they exist.
"AFNOR" is the standard of the connection as best I can tell. It looks like from the pics that the valve is considered part of the tank as in the UK and not swapped from tank to tank as needed as we do in the US. Am I correct or am I just looking at it wrong?
This is a problem I've been wanting to address. Different countries have different connections and it's hard for someone in the US to say exactly what you might need. I have the vision of putting together a guide for different areas of the world. I guess I should get started.......
Let's start with you posting a couple of pics of the tank and regulator fittings you are working with in Belgium and we will go from there.
No such thing as hopeless.....difficult maybe.....not hopeless.
This is my belief, but I am as unqualified as you to say for a certainty.
I can say with absolute certainty getting a bad concussion has not a single positive aspect involved with it. Not a damn one.