Propane Regulator for Smiths Little Torch

[Suzie]

Hi all - firstly I am very sorry for asking what I suspect is a well worn question but I just simply cannot find a definitive answer on forums or elsewhere on the interweb despite weeks of looking.

So I am just switching to a Smiths Little Torch on a Oxy Con and Propane cylinder system. I got the Oxy Con from Tuffnell's with the Smiths connector on it so that is all good. For the propane cylinder, originally I thought I needed a low pressure regulator so got the Silverline one in picture 4 but the connection (the little one) looked wrong as I had a screw connector from my arrestor. So I bought a high pressure 0.5 - 4 bar one but today when looking into what pressure I should set it on I started to panic and think that I'd got the wrong one as the Smiths little torch needs a low pressure regulator. So I'm thoroughly confused and won't proceed until I'm confident I have the correct set up.

So can anyone tell me which regulator I need for the Smiths Lt Torch. If it's the low pressure how can I fit the flashback arrestor on it (as per the picture) and if the high one which setting should the regulator be set on!!

Thanks so much in advance.