Just an idea to save weight on the rudder. Drill several (perhaps 50-75, maybe more?) 1/2" holes evenly spaced throughout the aluminum blade, sand smooth..then glue the foam on. The idea here to keep the structural integrity intact while removing some of the heavy material. The foam and glass will add strength back. If I recall correctly, I read a post on another forum about doing this with success. Your mileage may vary.
IDA chose the NACA 0012 blade shape for Compacs on their foiled rudders after testing various forms. Doug tried the 0014 design as an experiment. And judging from his boats' speed (sailed w/ him 2 years ago), as well as his reviews of the performance, no question the 0014 works quite well. Probably splitting hairs between the 0014 and 0012 on our little cruising boats.