Welcome to the forum Stu. I am also a reid but you spell my name reed. Any ammonia that you find that does not give rise to suds is fine. I live in the US so I use the stuff available from Ace Hardware but in the UK things like the material from various vendors like the one you have from toolstation look fine. The essence of a good product is one that contains only ammonium hydroxide with no detergents. That seems to be the case with your source.