Booking Appointments for a Chiropractor

I’m about to begin a new project for a chiropractor. He would like users to book appointments online and also have his assistant use the same front end to book appointments when someone calls in.

I have dug around and found out there is no third party add on that currently does this. rEEservation is almost perfect except it doesn’t do exact times.

I understand EE pretty well but do not know the first thing about building add ons. So my question is this…could I take something like Solspace Calendar events or Low Events and create a front end form that would just be someone creating an event (reservation) and somehow tell EE not to allow multiple events at the same exact time?

I may be reaching here but it doesn’t look like EE has many options for this functionality.

Any ideas?