There are plenty of them for sale on www.boatpoint .com.au . Maybe there is a message there Joe. They are pretty damn expensive things also. If that is the kind of budget you have, you might consider a Noelex 25.
Another thing to consider is whether you really want a trailerable yacht or not. They are convenient to store when you are not using them. If you choose a yacht that you can rig and launch on your own or set one up that way, you will likely go sailing a bit more often.
If not you will probably store it 99.9% of the time and sail it .1% of the time.
I had a Windrush Wildfire 23 ft trailer yacht that I set up for single handed rigging and launching and still did not go sailing as much as I should have. The ratio was similar to above.

Finding a sailing companion who is as committed as you are I suggest is the most important first step.
If your mind is set on a trailerable yacht, the Farrier design trimarans are well worth considering for the Whitsundays. The entry level is the fibreglass "Haines Tramp" and for $15,000 you should get a really good one. This one, although what you would call a day sailer/overnight camper boat, is a fast sail boat and can be pushed along quite well with a 4-10 hp outboard.
For similar money you could pick up a good ply wood Farrier Trailer-Tri 680 or 720 and have the comfort of a cabin!!!!
Google F Boats or Farrier Trimarans for lots of info. These are well proven yachts and being centre boarders are beach boats, so you do not need a dinghy.
Happy shopping. Cheers Cisco

P.S. I think the Macgregors are for power boat people who find the power boat thing is becoming expensive, so they would like to try sailing but do not want to let go of their perceived security of having a thumping great outboard motor on the back of the boat.