I doubt anyone from North America will be able to help you out, as you've got an Australian import of a strictly Japanese model vehicle that isn't sold over here.
I've only ever seen one or two Hiaces, there are several Delicas running around my city, and there's lots of Skylines here as well--owned typically by "boy racer" right-hand drive import vehicle fans.
But they are very expensive to import, register, and license and I can't imagine what they cost to repair over here since they are all so rare.
I would suggest starting at your local library--there may be repair manuals available similar to the Chilton brand books that we have here in North America (which cover just about every make and model of North American and some import cars). We've borrowed the Chilton book for our '98 Ford Explorer from the library in the past and it's been quite helpful.
The other thing you can do is to phone around to auto wreckers/"pick-your-part" yards/car graveyards and see if they have the part you need--often you can get a real deal on parts through wreckers. Years ago we replaced the radiator in our '83 Chevy S10 for a song by buying it from a wrecker compared to the over $400 that the part cost new.