I have absolutely no clue, but it seems half of the Sinningia speciosas I see are bred by Charles Lawn from your neck of the woods (globally speaking) and there are at least five contributors to the Gesneriad Hybridizers Association's seed fund. Perhaps start by looking for a gesneriad society?

Hi all from Oz
Just saw your comments and would like to keep in touch with fellow Aussies who grow Streps.

Join gesneriphiles and post an introduction. Ask for other Aussies to email you. There are quite a few on that forum, many great growers as well as hybridizers. This year two of our conventioneers came from Australia. There is an Australian African Violet society. I don't know if there is a gesneriad society too. But, other gesneriads are grown, shown, and discussed in AV groups.

Jon

Are any Aussies collecting lots of episcias? Love to hear from you !