Thanks Alun.
If you were after some wholesale quantities of DGB to roast up, I'd recommend two large and high quality growers from different ends of Australia - Skybury in QLD, near Cairns, and Mountain Top Coffee from NSW, near me in Nimbin. They both concentrate on growing high quality DGB for export markets primarily, although both also do have some retail exposure via sales to local roasters and cafe chains. Given their great distances apart, but otherwise identical attributes as high-quality growers using mechanical harvesting, wet processing etc, it will also let you check out some of the influences of terroir on local coffee taste.
If you were after smaller quantities of beans, from NSW you could try Carool Coffee Traders, Zentvelds and for example Rosebank Gold for an interesting selection, and from QLD you should try Coast Coffee from Bundaberg, or Jaques from near Cairns. These are all very nice coffee's, and yet each has their own personality.
Nat Jaques from Jaques Australian Coffee is also a regular visitor to your part of the world, I understand.
Steve