Hi,
Yes my planned paid product Resource Scheduler Pro would be where I would implement this, though I don't know when the first release of that will be available, and auto suggestion of next appointments may not be in the initial release, but is part of the vision for the product to support those scenarios. It will be designed for all kinds of scenarios from appointments with people, reservations of rooms or equipment. Basically you will be able to define any kind of resources, people, rooms, equipment, etc and allow users to schedule/reserve time with those resources. There will also be an ecommerce aspect of the feature allowing to define fees for use of the resource and collect payment for reserving resources.
Event Calendar Pro is really for events and not envisioned to meet the same use cases as Resource Scheduler Pro.
Best,
Joe