Dave,
Internally, use one of the specifically designed replacements for the ZW:
Z22:
ZW-232:
Modern Automotive Bussmann 19115 assembly:
Externally, I have known people to use PTCs (like the one you mentioned) attached to a terminal block for each individual output, but they take time to trip. You are much better off with a fast acting circuit breaker, many which have been discussed on the forum.