I've posted here extensively on FLinders before; I'm sure a search will turn up the appropriate thread. Flinders was the first Oz school to offer admission to international students; Sydney followed the year after, then Queensland. Melbourne is the newest addition to the pack that will likely eventually include all the schools.
Before accepting an offer from Qld or Melbourne, please make sure that they are eligible for US government loans; at one time Qld was not simply because they hadn't bothered with the extensive paperwork required. Melbourne is a new program and they may not have their "act together" as it were.
I do know that Sydney operates on a PBL format as does Flinders, but they have no exams until the end of the 2nd year. I find that a bit frightening. I have a friend studying there, in the 2nd year; please email me if you would like his address as I don't feel comfortable posting it here without his permission. Since Flinders has been going longer they have had more time to work out the "kinks" in the curriculum and have now graduated two classes, with a 100% USMLE pass rate for Americans and a good record of matching into residency. I'm sure Sydney students will do well in addition, but haven't any data for you.
You will find some restrictions on spousal employment. The government does not allow those on a student visa or their spouses to work more than 20 hours per week. This generally rules out professional type employment as does the Oz government requirement that it must be shown that no Aussie was fit for the job. Thus, "casual" employment is generally what is available. This means waitressing, child care, etc. To be honest the minimum wage is pretty good, but many of my classmates' spouses found that they were less preferred for such jobs than were teenagers - this is because of the law that requires employers to pay those over the age of 18 and 21 more money. Good service is a *rarity* in Australia, and most employers, IMHO, are not concerned about it enough to hire experienced, and more mature workers. Jobs are available, but the rules about working can be fairly stringent - depending on the state and the field.
Finally, the cost of living will be considerably more in Sydney, Melbourne and Brisbane. Adelaide and Perth are the two cheapest major cities in the country, with housing averages less than half that of Sydney. Consider this when choosing. Of course, employment opportunities may be great in the larger cities, off setting the greater costs.
Please feel free to email me should you have any further questions.
Kimberli "Like a sturgeon" Cox