I think Aquabound and Carlisle make great paddles for kayak fishermen. You want light, but rugged. Aluminum or fiberglass shaft with nylon reinforced fiber blades. Preferably yellow or orange - they can be seen a long way off. Lightest paddle you can afford - that way you can paddle for hours without too much fatigue and can push off against pilings, hard bottom, rocks etc. and not worry about dinging the blades.
I'll second Aquabound. I have one of their Eagle Ray models. It's incredibly light but so far has stood up to everything I've put it through. I'm temporarily having to use a borrowed aluminum paddle while my aquabound is being repaired (my fault for being stupid, not their's).
The heavier paddle has made me realize how much my Aquabound spoiled me. My kayak is a Wilderness Systems Tarpon 160, the fastest sit-on-top fishing kayak out there, and the borrowed paddle feels like it cuts 2mph off my cruising speed.
Drop some serious $$$ on your propulsion system, your shoulders and elbows will thank you.