User management plugin

Hi,
I’m about to build a wordpress website for a digital fabrication laboratory which is supposed to have a pretty complex structure, and I’d need a few plugins in order to make it work as it should, so here are the specifics I need:
– The user should be able to register and have access to his own personal page, in which he will be able to keep himself updated about how many credits he has left and other informations (so basically the administrator should be able to manage the user’s personal informations).
– The user should have the chance to book the courses and pay for them (through paypal or credit card).

What are the best plugins for these needs?

I appreciate any help you can provide.