The authoritative dataset for Victoria is VMAS, the Victorian Mapping and Address Service. Alternately you could try looking at the G-NAF, the Geographic National Address Framework from the PSMA (Public Service Mapping Agency). PSMA offer an online geocoding service that can take advantage of the VMAS and G-NAF address datasets (VMAS feeds into G-NAF but is slightly more up to date). My understanding is that the PSMA are currently in the process of upgrading this service.
With any luck your university will have access to this data - you may need to talk to your advisor. Alternately if you're doing the research in conjunction with any public service agency you should be able to get access through that agency - talk to the GIS manager. If you don't have access I think it can be quite expensive, but you may be able to talk to the PSMA about access as a researcher.
Alternately you could take a look at the ArcGIS World Geocoding Service, but I don't know how accurate that's likely to be.
As a last resort if you have access you could attempt to build a geocoder from the VicMap Address dataset, but that's probably going to be a pain in the long run. And again data access is prohibitively expensive if you don't already have acess through your university.