The decision is often...buy it or build it?
Given the limited amount of programming and development time during the robot build portion of the FRC season, it makes sense to focus on the implementation of CAN in a robot design rather than spending time fabricating cables.
Building CAN cables is not rocket science but it is one more thing to do on a long list of tasks in a typical robot build.
If you decide to
build it...see the Texas Instruments website for
Stellaris Jaguar CAN information.
If you decide to
buy it...see the eStop Robotics website for
CAN cables inclduing a
CAN Starter Pack.
Either approach will give you access to the advantages and features of a CAN enabled FRC robot.