Sydney and Melbourne have decent business schools - with your experience, you'd probably be best off with an Executive MBA and continuing to earn. If for some reason you can't find work then a fulltime MBA might be worthwhile (low opportunity cost, get the MBA out of the way). Taking a few months off? - Certainly an option (and an attractive one at that if you want to see Australia and NZ), but I'm guessing you wouldn't have put the MBA options on the table if you didn't really feel in need of something developmental to your career.