Can someone give advice on which of two rear wheels to use that I've now acquired?

Simply by waiting patiently, I've been able to score a few good deals on Craig's List. Now I have both a complete wheelset AND a second rear wheel.

The rear wheel belonging to the wheelset has a Shimano Ultrega FH-6600 hub and a Mavic Open Pro rim with 32 spokes. The other rear wheel has a Shimano RSX FH-A410 hub and a Mavic CXP-10 rim with 36 spokes. I weigh 205 pounds (93 kilograms).

(Of course I'll use the front wheel from the wheelset.)

If I were twenty pounds lighter then this would be a no-brainer. The Ultrega/Open Pro wheel is the better one. But I'm not.

Your advice, my friends?

P.S. Might anybody know of an LBS in New York City that may be willing to give a good deal on some sort of trade-in for the equivalent Ultrega/Open Pro wheel with 36 spokes?