Hi. I’m about (next 3-6 weeks) to fly a Cessna 182RG from Auckland to Gold Coast Airport. I’ve done this several times before but the last time was 10 yrs ago. Things have changed dramatically since then. Bureaucracy has well and truly made things a lot more difficult, particularly at Lord Howe. With the range of your aircraft you’ll need to transit through Norfolk and Lord Howe. Norfolk has 1000 litres of fuel currently available at $7.50 Aus per litre. I’m yet to find availability at LHI. 20yrs ago Customs Clearance at Gold Coast was free. 10yrs ago it was $200. Today I believe it is $1000. I have HF but there are usually commercial aircraft who will relay for you on the chat frequency 123.45. I believe you could self clear at Darwin but from there on I suggest you use a handling service or you will have problems. Good luck.