I think it's weird that so many people have read this and no-one has replied. I would always reccomend an A4 that folds to an A5. When I was doing all my early VFR flying it was really useful to have an A4 so there was room for everything. I needed a lot of space and could record everything on one sheet. Once I started radio nav I preferred an A5 and didn'y want to buy another so it was good to be able to use my first one folded in half