Hello Anz
This is my first post on this site since I joined and I was drawn to you post because I am a social worker and my hubby is a refergiration and airconditioning engineer. We were also looking at migrating to Melbourne because we attended a seminar in 2012 and spoke to immigration representative who sold the region of VIctoria to us. I joined the sister site "life in Victoria" to get more information and so far so good. We have employed migration agents as well who have informed us that we will be eligible to apply for 190 Visa based on our points we have at the moment. As the main applicant social workers are being sponsored for 190 visa by Northern Territory, New South Wales and ACT. Which blows our initial plans for Melbourne out of the window.
You will find that your location of interest is often dependant on your points scoring and type of visa you can apply for. At least this is what happening to us. However I have been informed that after 2 years it is possible to move to another region if the entry visa used is the 190. Hope you find this information helpful.