BLKPNY
Each state does their own thing. Would suggest you make contact with one of the committee members from each state you wish to be involved in. As you are in Victoria, I assume Victoria would be of most interest to you however that assumption may not be correct. I am sure the Victorians would be very happy to discuss something, particularly with Ballarat Nationals fast approaching (Easter).
In NSW, we have magazine advertisers (annually or short term available) as well as sponsors supporting a lot of our major events throughout the year.
I would recommend you check out each of the State web sites and shoot off an email with your contact details to the President of the state(s) you are interested in.
Good luck but if any difficulties, send me a U2U message.