Eating In: Diaper Covers

How Many Diaper Covers Do I Need?

I am trying to figure out how many and of which kind of diaper covers I need to order for cloth diapers???!!!I will be using ABC Diaper Service, but they only offer 1 type of cover, unlike Tiny Tots who has multiple types. What should I do and how many should I order? Is there another website to order good diaper covers from?