Wow, I found someone who is looking for something similar.  I am looking for a "simple" video replay for girls volleyball. We have the ability to mount 2 cameras, wheel on a cart a DVR and TV's or projector. 
  
Question: Which DVR would you use?  The Tivo brand boxes require service and do not recognize a camera, either does the Cox DVR box.  We have old camera's and willuse S video cables. 
  
Suggestions for DVR box? 
  
I do not need  a delay ssytem.  The coach would indicate a player made a mistake .... then she would go to the remote control, rewind ...see her mistake, make the corrrection and resume playing.  The recording should be continuous