I don't think you need any surge suppression or extra breakers at all. I would also suggest that if you have no plans to use DCS the TVS diodes sprinkled around aren't really doing much. A DCS TIU has a TVS on each of the 4 outputs that interface to the track, these are between the track and the electronics inside the TIU.
As GRJ stated, TVS diodes are meant to protect sensitive electronics and the best place for them is right at the board being protected. If a spike comes down the line the diodes short the excess to ground so they don't travel into the electronics. That is why there is a recommendation to install one in the engine.
Sprinkling a few TVSs around the track may give some protection. But if you think about an engine sitting on the track between diodes that engine will be subject to any spikes between the diodes. So are they really helping?
That's my opinion, subject to slunk jeep. 
