Amember integration with third-party webservice

We currently are using amember and a few integration plugins to control access to the digital editions of our magazine. We are going to no longer manage processing the payments ourselves and instead will need to pull user info from a third party using their webservice calls. The amember database will no longer contain user info, but instead calls will be made to third party service to get all the data that amember now pulls from it's own database (whether the user is active, what products they should have access to, when their subscription starts, etc). All of this should be able to be calculated from various fields in the third-partys database.