I'd get it vaccinated asap if you plan to be moving anytime in soon. The rabies jabs take the longest but as these are not standard for UK based animals this is more a one off so you'd need to allow six months. But nothing wrong with ensuring you've had your cat vaccinated for all it needs before hand. Also it might need other blood tests for stuff and if it fails that a re test after treatment etc so worth investigating now what the situation is.
Also if its not neutered I'd get it done here and save on costs the other end. IIRC you need to chip, register and so on with cats as you do dogs. De sexing gets you a cheaper reg rate I seem to remember reading. If your cat is picked up and isn't chipped, it often doesn't get long at the pound, sometimes only 48-72 hours before it could be PTS. At least if its chipped you stand a good chance getting it back.
Read the AQIS site for all the info. Number 11 on the list is general vaccinations. TBH though I'd not leave it to the last minute as it really isn't worth the risk stuffing up thousands of pounds for not being organised and getting it done in plenty of time.
Time frame: Between one (1) year and 14 days prior to export.W! - As of 1 March 2012, all import permits for dogs will be issued with a condition that vaccination for Bordetella bronchiseptica (kennel cough) iy.Vaccinations must be valid for the entire quarantine period in Australia. All vaccinations must have been administered within an AQIS approved country.
- Cats must be vaccinated against feline enteritis (also known as feline panleucopenia or feline distemper), rhinotracheitis and calicivirus.
And contact a pet shipping agent or two to see what blood work etc you will need if you are not sure. And get some quotes in for shipping and quarantine and all that.