I would recommend the PowerHouse 180 and Legacy PowerMaster with your Cab2. The PH180 has plenty of power for your lashups and has a very quick circuit breaker. You would need one PH180/LPM combo for each loop of track you want to run conventional. Below is how I would set up the circuit.
The PSX-AC is an exceptionally fast circuit breaker (with other capabilities) that I use for extra protection even though the PH180's CB is very good by itself. You could also use a fast acting fuse. I would recommend you add the TVS shown; many on this forum think it is very good protection for your engine electronics.