The search and cost of a suitable single piece of wood scared me off. I followed the plans and instructions, for a couple canoe paddles I built, from Gil Gilpatrick's book ($10 at Amazon.com) and really like the final results.

His method laminates three pieces. The blade and middle 1/4 inch of the shaft is one piece of cedar. I used ash for the two outside layers of the shaft. The blade tip is reinforced with epoxy soaked nylon rope and the blade is covered with epoxy and glass. The advantage of his method is it creates a rugged flexible blade and a strong light shaft.

When laminating strips from the same piece of wood you should not only rotate every other strip 180° to cancel stresses but also flip them end-for-end to keep any imperfections from lining up. It is also preferable to quarter saw the lumber so the grain on the shaft is perpendicular to the blade

If you buy Gil's book and like how the paddle comes out, you'll already have plans and instructions to build a stripper canoe.