Arrow and Arafura Cadet specs are on the National (AUS) website
www.arrowarafura.com
Minimum Weight (hulls and fixed fittings) 50 kg
plans are $30
I like the idea of building the F12 and then if it gets outgrown building 14ft hulls to transfer the expensive bits over. The main sail area for the F12 is only 0.6m2 smaller than the Arrow, with its high aspect rig should work fine with the 2.6m2 jib. The Arrow has a metal framework for the centreboard which the kids and I don't like but it works unbelievably well and leaves the decks clear to sit on. When the kids go out they just pull the rope and cleat it like a dinghy and when they come back to the beach they release the cleat and the board comes up.
regards