The boatpoint site mentioned above is a good one.
There are two good sites in Australia
; the other one being The yacht hub (Boats for Sale - Yachts for Sale - Used & New Boats @ The Yacht Hub
I prefer tacht hub - it is easier to use, presents the information better and gives more details. Nevertheless, it is worth trawling through both, as ther are lots of boats that are listed on one or the other, but not both.
Personally, I don't think there is a particular type of boat that people will be looking for here, any more than anywhere else, at least. A well found boat is a well found boat, and people will recognise that. Of the mainstream production boats, Beneteau
is far and away the most common, followed by Jeanneau
. Hunters are Catalinas are rare.