Looks like I have more parts to buy and also there is a Black Friday sale, whatever that is, on Ali Express. After much examination, looks like I want these NEMA 17 motors from Stepperonline. I'll save like $3 in the sale, which is about 3/4 of a cup of Melbourne coffee.
These motors seem to have enough torque, seem to be ok for noise, are broadly recommended and sell direct on AliExpress. They are rated 12v to 24v. I going to attempt a 24v build, but if that doesn't work out it appears I could change my mind and make a 12v build by replacing the Hotend and setting my heated bed to 12v instead of the 24v setting. The Prusa i3 MK2 was 12v, but the Prusa i3 MK3 was 24v, which is my influence.
Stepperonline have an Australian store with stock, but they didn't seem to have the motors I was after for a good deal. They do have power supplies for Australian use, and also steel L brackets for mounting the motors which I'll seek advice about. Seems like they get some local AU business from me too.