Thanks for the replies.
I am very open to an end to end layout, the plan is to build a shunting yard so a continual loop wouldn't be absolutely necessary. I had planned to have 2 boards (2 3x3 or 2 4x3) for easier storage and split this so most, if not all the buildings are on one board and the other board is predominantly track and can be stored upright.
I do prefer OO to N, more detail better running quality and I have a liking for Athearn but the worry was that the board would look to crowded and cluttered and not in an intentional way.
The hope is that this will only need to be stored occasionally.