I am from the UK so don't know the exact details of Aussie funding.
Do you have your own funding? That changes the dynamics significantly. If you need funding you generally have to stick to their research areas. Generally supervisors want students that match their research interest and you can find that out by internet stalking them or emailing them individually. They more likely to be polite if you try and engage them individually.
Not an accountant but that research topic sounds very ambitious. I see, cloud computing, digital payments and cyber threats which are each huge topics and make your proposal look too big for an MRes. I would narrow the criteria by dropping one of them or focusing on a specific sector, so that is manageable in a 1/2 year time frame.