I used to think the same thing until I tried some of the fancy paddles. The Werner guide stick is nice and light, the bandit (the spooned canoe paddle) is sweet for rafting, but it takes some getting used to. Jimmy Snyder's "Jimistyx" are irregularly shaped and very easy on the shoulder. If you do buy a wooden guide stick, however, I highly recommend Kenny Kiley's "Blunt Family Paddles." I don't think Kenny has a wedb site set up but you could probably find him running Gore for AVA in the summer.
As for size, the standard Carlisle "custy" paddles are 60" long. Usually people chose slightly longer guide paddles 63-69".