Plugins for "Membership" viewing License Keys

Here is the scenario... I am selling a desktop app that has unique license keys for activation (like microsoft)... and am wondering how to create an environment where the user can login and see their license keys. I have looked at the WPMU premium Membership plugin... but I don't see how that could work. I am also evaluating other Membership plugins (Memberwing, s2member, etc)... however, I still can't seem to crack this pickle.

Ideally the user would be able to view their subscription and cancel from within the logged-in environment. (Then I would manually revoke their license keys).

Can anyone point or push me in a direction.