The anode is a gret idea, BTW. I think zinc is the standard metal used for this purpose and you can buy zinc anodes at any marine store. One for the mast and one for each beam. Sounds like a plan, especially for these boats with painted masts and beams. Adds a few ounces weight at most.
I predominantly sail my boat in lakes but hit the ocean 4 or 5 times a year. I've been planning to add a few anodes around the boat. If you do decide to attach anodes to your major aluminum components, be sure that it is electrically bonded to the aluminum. Remove any paint, anodizing, or powder coating where the anode meets the aluminum. They must be capable of conducting current to the anode for it to have any affect.
