I used to try to build everything with full-length strips, but I found it really hard to handle those long boards. "Stuff Happens" over that 17' length. I used to make scarf joints "across the width" of the strips, but I found that after epoxy & varnish, they look pretty conspicuous. Now I make the joints "through the thickness":

________________ ____________
________________\\___________ }1/4" across the thickness, side view. The angle should be more acute than this illustration.

I do these on the bench top disc sander, using the little fence at an angle. I like to glue them together before fitting on the boat , by clamping, but some clamp the joint together right in place.
Woods-Cedar, pine, and redwood are good choices for light weight and easy working, but use whatever you want. Hardwoods will add weight quickly, and are less "forgiving" when shaping joints.
If you are debating between Cove & Bead vs. Beveled joints, you will find lengthy debates on this board about the pros & cons of each.
My $1.98 worth of philosophy-if you like to improvise, learn-while-doing, problem-solve, create creative clamping techniques, etc, you will love this project!