Selecting a motion sensor

Hello

This is my first post, I want to build a hockey stick puck handling trainer for my daughter, I would have 5 sensors under a piece of lexicon, I would write a program that would randomly select a sensor, once a puck has crossed over the sensor twice to would randomly select another sensor, once the puck has crossed that sensor twice the program would move to the next sensor, the sensor will detect when an object (puck) has crossed over it. Also I need a sensor that would detect when a puck as hit it. Any help would be great

If you need more info just ask, thanks in advance

DB