You can live anywhere within 45mins of Melbourne as long as you are on the tram ot connex train line you will be fine, whether a suburb is a good place to live is apersonal preference and very difficult for someone else to judge, there is good and bad in every suburb and the closer you go to the city the more expensive it is, I think for 300 dollars a week you won't get a good rental near the city, you prob need 4-500 a week for that but choose either pay for it in transport costs to work or pay for it in rent its up to you.If you have a job get a letter from your employer stating the length of your visa ie mine was 457 so she stated on the reference that I am a highly skilled midwife wilth impeccable references and that she planned to employ me for a minimum of 4 yrs, I think thats what swung it with the estate agents and bear in mind that the landlords here decide who rents their house not the estate agents, so on the application form sell yourself, provide written references and follow upin a few days if you haven't heard anything, have your bond(= to one months rent ) and your first months rent easily accessible
Good Luck all, you will get there in the end Jabba