I'm looking for advice on the best way to offer

I'm looking for advice on the best way to offer the following feature to my sub site customers.

Here is the user story:

As a subsite administrator I want to be able automatically invoice my site members so that I don't have to manage their payments manually.

Acceptance Criteria:
Site members that pay by credit card are billed according to different payment plans.
Site members that pay by check are sent an automated invoice to remind them when they have to pay.
Site members can use any processor they prefer so as to allow them to get the best rates.
All membership payments are tracked and updated automatically, and can be updated manually as well from the dashboard.
Site admin can create reports on individual members or groups of members or entire member list.