Difficult question to answer, depends on lot of thought regarding amount of space you have for layout, how deep your pockets are and what you want on your layout and your ability putting all into action and time.

Put down + and – on paper and visit good local model Railway shop who can give you honest answers regarding options available.

Agree Callum days of pen and a book seem along time ago but memories we all have and yes no longer either green or blue locomotives but were all still kids at heart so keep the photo’s coming and suggest rest of group start posting few on noticeboard as well.