If you don't mind running the conventional stuff from the transformer location, you can just use a standard transformer for power, it'll be the cheaper option. You can frequently pick up a reconditioned post-war ZW for around $150, just add some external circuit breakers in each track feed.
The other bonus of a PW transformer is the pure sine wave, certain older MTH locomotives with Protosound don't like chopped waveform transformers.
