I know that both The Vault and Seedsman have active representatives here at the forum, which can be helpful if any issue pops up.
However, Australia seems to be a bit of a special situation in terms of the "free nations," lol. I have gotten the impression that your Customs agents are, well... really determined to do the best job that they can . Therefore, if it was me, I would probably call or email a few seedbanks and ask them what their success rate is in shipping to Australian addresses (and definitely choose the "stealth" shipping option). I might even consider trying a domestic seedbank. I suppose that would depend on the answers I got from the forum sponsors that I contacted (I don't think any of our current ones are located in Australia), both because I believe in supporting the businesses that help keep this forum running and because people seem to be happy with the selections at those businesses and the service they receive.