I'm not sure if the trial pack comes with the extra booster or not - they come with two boosters - a long and a short one - but you can get one that you fold up to go either in the nappy or on the outside between the nappy and the wool cover for added protection of a night time.

I would say about 4 PUL covers - switching between 2 during the day, but have a few spares just incase for POO explosions!! LOL

And I prefer the bamboo - much softer and a tad more absorbent.