As Clockwork says, cruising boats can't really use assymetric boards. You have to retract the windward one by pulling it up after every tack like the AC45 cats did. So your boards should be symmetrical, even if they were designed to be assymetric for some strange reason.
My two cents - get your diving gear
on, our with the boat on the hard
, really check for the minimum width of the case. I have had issues with building boards 1 or 2 mm wider than they should have been. It can be very hard after you add some filler to smooth out the weave and then paint
the thing. It is always easier to build the boards first and then the cases. So err on the side of caution and leave 5mm at least for glass, filler and paint
I don't like using ply for boards as half the grain runs in the wrong direction. If you can get ply with only one orientation of veneer, it is called bendy ply in Aust, then that is okay, but I like cedar better.