Yeah I worked at YMEN for the last 5 years and the only aerobatic aircraft I saw that is (or perhaps was) for hire was a Citabria rego VH-SAX and is owned by an engineer. Its white and blue and last time I saw it online was with Interair however that was over a year ago now. Try giving them a call perhaps the aircraft is online somewhere at EN! otherwise Moorabbin is definately the place to go for aero's.
Hope that helped.