Vince
I went through something simalar earlier in the year with a 5.4 metre boat from Brisbane. I rang boat movers and it was expensive but nothing like that.
It will not fit on a train.
towing i could not find a car rental company that ; had a car for hire with a towbar; hire a car and let you tow that weight if they had a towbar; or take that vechile from the state! then some would want a return charge.
If going the truckie option i would want some assurance that the truck knew what he was doing.
Also i would suggest flying up 1st to do the deal and see it loaded. I didnt end up getting my boat as it was not how it was described to me after a detailed grilling of the broker!
Your best bet is to go get it your self! and take up an offer from somebody like Ross (although you would have to talk bloody etecs for 2000+kms) or try and cut a deal with the owner to get it down here, he will know more people in Cairns than you.
Sorry to a misery guts, but it is better you be warned? I do have a contact who is the machinery business in Brisbane and Mackay and could ask them about transport people if that would help? No promises but he may be able to steer you somewhere, PM if so.
When in NSW, boat rego should be straight forward but the trailer unless it is from a newer trailer manufactuer and they have a plate showing the tare weight you will have to weigh bridge the trailer with out the boat for rego.
Remember QLD hav REVS for boats as well, you have to pay and get a check on Hull, Motor(s) and trailer all seperatley.
Good Luck