[Zope] Zope product with folder as base class

When creating a container product in Python one first use ObjectManager. One can also use OFS.Folder, ZCatalog, BTreeFolder. What's the difference between these and SimpleItem? Some friendly hints and advice on the best base classes anyone? ...for a product that will act as a container for quite a few prefferably searchable objects. What I care about the most is performance and scalability. Peter