Postwar ZWs are fine, but the units you mention are less power. Before spending bigbux for a Z4000 or new ZW, I'd consider Powerhouse 180s. The deliver 10 amps, have a very fast electronic circuit breaker, and are reasonably priced (cheap!). I have one feeding 2 TIU channels for zones where there is little multiple movement. One could easily power one of my mainlines, where 3 locos running at the same time is commonplace.