I would avoid the MTH Z4000. Its circuit breaker was not designed to protect the delicate electronics in today's locomotives.
To be fair, though, no transformer's breaker will protect the delicate electronics in today's locomotives from the cumulative damage caused by spikes, as breakers are for current limiting, not voltage. That is an entirely different issue(search the forum for "TVS").
Use any transformer you wish, ZW or otherwise, but your immediate issue is a track/continuity issue, not a transformer/power issue.
