Hi Nicko,
Ya gotta sort out the gunnas from the going to's.
How long will it take to build your f12?
Life's too short. Buy a mari 4.3 and go sailing next week end.
When your ready to spend 200 hrs building a boat, get some mozzie or f16 plans and build a boat that your daughter will be able to grow into and race together with her dad. Here's the f16 link for two homebuilt f16's. Cat rigged 16 footer one up awesome!
http://www.formula16.net/content/view/40/57/lang,en/
Spose it's all about what you like doing.
Good luck with the designing.