Use security assist to create the login page and registration pages.
it sounds like you only need admin login, so after registering the initial user, you can add protection to the registration page so it cannot be accessed.
as for storing credit card details, that is a very bad idea and in many cases can be illegal.
if you do store the credit card details, make sure to use encryption, and make sure to delete the information form the database once you are done.
Universal Email can be used to send information in an email, bit you should never pass credit card information in an email.
exporting the data to CSV would require hand coding to accomplish.