Thank you for all your advice so far.
Certainly, talking to my local model shop would be ideal, but I have Asperger's so that's not so straight forward! Going somewhere I haven't been before, talking to someone I don't know is something I would find difficult. My partner would help here, but she doesn't know everything I want to ask, and it's still uncomfortable for me.
I don't plan on buying all the locos at once, I know what controller I would like and any track I buy will be used as I have a few similar layout ideas.
I know I would like the locos mentioned in my first post and I'm slowly working out whether I need to buy the relevant Hornby, Bachmann, Dapol or the Heljan with your help.
Neil