As Tony pointed out you could try Aikikai Australia http://www.aikido.org.au
They have dojos around Melbourne and the main dojo is near the city with good public transport access and classes every day.
They are holding their annual Summer School in January and the guest instructor will be Yamada Shihan.
All the instructors are direct students of Sugano Shihan ( see http://aikidomelbourne.org.au/pages/...nstructors.asp
for instructor profiles)
But as is always recommended here, look around and try a number of schools to see which best fits your needs.
And yes I am a member of Aikikai Australia