Hi Gnangarra,
it is a fact that has been in discussion a few times on this list and elsewhere that Wikimania in Australia would be a wonderful thing but something that is not likely to happen, due to the cost of getting everyone there. That said it may not be entirely impossible, but difficult.
Anyway I know that Ellie Young is happy to receive any proposal you may have and do a proper due diligence on it! Get in touch with her and see if you two can work out something that is doable, despite the costs!
/Manuel