The Republican Party of Australia is a single issue party, and do feel the need to make clear that they are not associated in any way with the Republican Party in the US (not that I can blame them for this). Their single issue is the transformation of Australia from a constitutional monarchy to a republic. I couldn't see a preferred form of republic (Governor General directly elected, elected by parliament, or President with executive powers directly elected) but I think they're a bit more focused on the principle than the specifics at this stage.
Other changes that they want to see are a Charter of Rights, a review of the current three tiers of government with an aim at reducing this to two, multi-member electorates (although 75 10 member electorates might be a bit too much), a land tax, clearly defined boundaries between church and state, scrapping the carbon tax, and zero net migration. A bit of a mixed bag there.
The Republican Party of Australia have candidates for the senate in New South Wales, Queensland, Tasmania, and Victoria.