I am so glad I asked the question!
My original idea of a 13" standard laptop for working with inDesign is obviously completely hopeless.
However, the setups described so far, are too expensive for me at this stage.
Will probably settle for:
Screen: 23"
RAM: 4GB
CPU: Dual core; i5
500 GB HDD (i.e. not SSD)
What do you think about this? Am I going to be frustrated by slow processing and lack of screen definition (45 year old eyes in this case)?
Anyway - your comments are much appreciated. Thank you.