I agree with Rob. I grew up around a "ole boat shop" in central florida. where they used cypress. muatly the old fashion 12-16 ft. flat bottom fishing kind. The sides usually were single plank of the 16-20 in. width and full length. made springing the sides much smoothier.
A trick for the bottom planking was to hammer\compress the edges with a concave iron, then plane the edges smooth. After the planking was placed, butted togather, with no caulking, it was nailed off and the ends cut smooth with the sides. Chines were attached and the boat was run-off into the lake to "swell". They never rotted or leaked. Dry they weren't "too" heavy, but bor after they got wet. My oncle used to toll the lake wiith a little 3-hp evenrude - caught my first bass in that boat.
Just a little food for thought. Not knowing what style of boat you are planning, info might, or moght not help.
Best with the boats.
Mac:-D