You'll probably want to just take the camera.c and tracking.c (and their related .h files) and make a copy. Then change all of the static and extern variables to slightly different names. Then just call the camera handler and the servo track in User routines.
http://kit.kitkorp.com/frc_camera_doublecamera.zip Shows the laziest of the lazy version of this code. There are some changes marked with "Brian" in the tracking2.h, tracking2.c, and tracking.h to limit the scope of each camera to half on either side, and reverses so they each start in the middle and spread out.