Camera setup for quick preview/editing
If your cameras have a LANC port, you can build yourself a LANC controller using arduinos: 


http://controlyourcamera.blogspot.de/2011/02/arduino-controlled-video-recording-over.html?m=1


Or alternatively get a cheap lanc controller. 


http://pages.ebay.com/link/?nav=item.view&amp;id=281983277383&amp;alt=web 


Depending on the camera you are going to use, like the other replies mentioned, there might be options to control your cameras as well through a regular remote control or control over USB.