We need a WHMCS module which will custom the order form of a package. It will give an end user an option to add a service for there VPS/server.
The module will have to hook the order if the service is selected. We will add the registration (our api) to our service by our self. Just hook the event
The admin needs an admin are to enter api-key and some other (few) settings. Also, an admin will have an option to enable/disable a client from the service..