Confused - nebulisers also VAT

Hi all

Hope you are all well.

Now i am confused. What is the difference between the philips respironics elite and the portaneb sidestream. Does anyone have these and how long does it take you to neb 2.5ml of ventolin or saline. Also does anyone think that the elite is underpowered. I have spoken to suppliers/read reviews but i am still bedazzled by the whole thing and its wearing me down now

Does anyone know whether we are VAT exempt and how we prove it like can we just sort it out or do we need some sort of doctor authorisation?

Any help most appreciated