All depends on the speed. First of all write down a framework of operation. If all the demands and questions are clear you can fill in the details. Then you start selecting the hardware and start programming.
Out of the blue starting with hardware can give you good result but no garantee to get to your point of destination. Just as a following robot with obstacle avoiding capabilities.
So if the details and demands are not clear in your head, how can we give you a decent answer ?