Hi John Rodrigues, Here are some other inputs to get this task done in a simpler and quicker way.
We can move the robot head like a dual axis solar tracker as in the link below
We would use an IR sensor or any other proximity sensor to detect where the person is and turn the head towards him. It would be a modified version of obstacle follower.
To overcome the difficulties of using normal IR sensors in a well-lit environment(especially with sunlight) we can use sensors with filters like this
any other sensors like the sharp sensor or ultrasound sensors can also be used. But the system appearance would be compromised.
For image processing, I suggest using a raspberry pi as the main controller as it can do image processing onboard as well as do the tasks which Arduino is currently doing.