Hi Mike

Rob has given you an extremely thorough run down on what you need.
I would like to add just one thing.

I have found my best option for selection comes from the Wholesalers rather than the local retailers. Try to talk to contractors and find out where they buy their materials ( wood ). Don't call them... go there and mention that you are building a custom boat and are interested in Blah, Blah type of lumber and can't find anything in the area. Then ask if they will sell to you. Chances are they will make exceptions... and list you as a contractor. I've done it several times. They don't do this publicly but will often make an exception for some specialty project. They may have minimum order limits like $100 or something like that, but it's worth a try...
This way you will get the wood before it has been picked through by the public.

I use two yards that way here in Fresno and I get good wood and pay contractor prices for it.

Unfortunately, for marine grade plywoods and WRC, I have to go to the coast.
Still worth the trip... fresh sea-food for lunch... a little fresh marine air and off to home again..

Take a few minutes and try the wholesalers... It may get you a little better quality wood at a cheaper price.

Rehd