Towing Laws?

[montyv8]

I'm wanting to tow a car interstate later this year, and I'd like to know what the go is with laws regarding how much you can tow (weight-wise).
I've been told by a few people that the tow vehicle has to be equal to or greater than the load it is towing.
I was planning to tow my XB coupe on a trailer behind my XB ute. the ute weighs 1500kg, and the coupe weighs about the same, then theres the weight of the trailer (standard hire trailer you see at servo's, anyone know what they weigh?).
The ute will tow it no problem, I use it for that quite often, but I don't want my wallet to get raped because the load I'm towing is 100kg (as an example...) heavier than the ute.
Also, do they use the standard kerb weight of the vehicle as specified by the manufacturer, or the weight loaded (ie if i have a couple of hundred KG's worth of tools, trolley jack, spare rims/tyres, spaer fuel etc etc)?
I'm guessing its the former?
I'm interested in what the rules are in all the states/territories are, but mainly NSW and VIC.
Also interested in the penalties if you get busted..
thanks