Thanks for all the replies.
I do see that the 17 is more popular, didn't realise there was much difference in the rigs on them though, to my uneducated eye they look the same, or between the boats, they are not just the same thing in different sizes then? What makes the 17 better then? Multi-passenger I expect to have, though will avoid rough water.
One thing I did want is the abiility to experiment with rigs, and I think I saw that the 17 can be build with a third mast step so you could set it with just one mast and maybe a lug sail or something?
I do have to consider the costs though, down here in the antipodes a sheet of cheap, heavy, environmentaly unfriendly 6mm ply is $45, the good stuff is $120.
Simon.