I believe there is no modern oar available that has the proper balance and dynamic flex. One has no choice but to make your own if you wish to preserve your wrists, elbows, tendons and attitudes. 

Clint Chase taught me oarmaking at WoodenBoat School in 2014. It turns out you can make a straighter, finer, more perfect oar by carving it than any other way. My first pair were of Eastern Spruce, and worked magnificently for exactly two and one-third Grand Canyon trips. Then they both failed catastrophically on entry to Unkar (Right oar) and Hance (left oar).  I then went back to ash for my main Grand Canyon oars, but am now experimenting with Port Orford cedar. I like it.