We actually secured our rental through a lead on this website. However, it did go through a rental agent and we just filled in all the forms and it ran smoothly. For ID, we used our UK details, passports and sent a copy of our visa.
We were told though that the landlord had the final decision, who luckily was originally from the UK for us. We did also have to pay the bond and a few weeks rent to secure the rental.
If I was you, I would try for anything you see online and on real-estate.com as you never know. However we have visited Moana and knew where we wanted to be based. But saying that I think that all the south suburb's are nice, we looked from Hallett Cove to Moana and loved the coastline.
We are still hoping to be out late April, how are your plans coming on?