Trailers

ArieB,
I've just gone through a similar process and ended up getting mine custom built by Coota Campers in Cootamundra. They were very accomidating with what design I wanted and were very competive in cost. I also live in Sydney and didn't like the attitude of most Sydney based Trailer manufacturers. It was case of if I didn't like their design too bad.
Cootamundra is about 4 hrs drive from Sydney so to pick it up is just a day trip for me.
It also helps if you have an idea on the size and design requirements before contacting manufacturers. I spent nearly 18 months checking out different trailer designs at the majority of the 4wd and camping shows in the Sydney region.
I actually settled on Coota campers at the Port Maquarie Show when we were up there on a weekend away. I didn't know the show was on until we got to Port Maquarie. Jim from Coota Campers is very easy to deal with and is very flexible with non standard designs.

Above all look around and don't be pressured into buying the first design that you see.
Cheers Kev

You can try trailercity (www.trailercity.com.au) in Rydalmere, they do all sorts of trailers and can customise them to whatever you want pretty much. Elvis is the guy I've been dealing with, very receptive. I've just ordered an offroad spec trailer from them myself.

No connection just impressed with the setup they have.

Can't offer any suggestions where to look for a trailer, but a tip on what to look for. Make sure your trailer has real springs (eyes both ends) not slipper springs as they are way too rough for off-road use. Also a good idea to make sure the A-frame is decent strength. I broke the A-frame on my trailer on the Oodnadatta Track, with pretty spectacular results, and found that the steel was only 1mm thick.

Live and learn
John