Hi Preston Lass,
We are in the same boat as you except I've got kids older and younger kids than yours so can't really comment on schools for their age group. Have a look on the victorian schools website. Most areas look ok for families but I'm sure there are places to go and not go to although I haven't read any bad one's yet. My OH is also a plumber, I have been told that he could earn about A$100 a day, however that's probably after he gets aussie qualifications after 2 years at evening school, so bare that in mind.
Have you looked at getting your provisional licence yet? If you haven't look here
Plumbing Industry Commission, Victoria, Australia - Home Page we contacted a Nicholas Payne who said if we contacted him with a postal address he would send the necessary forms etc for this,
nicholas.payne@pic.vic.gov.au .
Hope this helps a bit.
Helenx