Yep,
Jerome, Ali is right, there is no contest whatsoever. Cooktown in possibly the windiest place in Australia, let alone the East coast.
Cooktown cranks. You'll need only a medium and a small kite to visit Cooktown. You can camp at Archer Point for free (last time I was there anyway) and the riding is wicked! You'll need to take everything in with you as there are or were no facilities at all. Just a grassy spot behind the beach and lots of windy water. A little bit croccy and a wee bit Tiger Sharky too but so worth it! But water and beach is clean and it is quiet.
The best of flat water and also has the closest thing to a surf breaking wave in the entire North East Coast.
Cairns is nice if you love riding in poo brown, choppy water, and moderate winds. It has night life and such, but for pure kiting Go north young man!
Good winds,