I got the foam from www.slofly.com It works good, just have to use a sharp razor blade or else it won't cut out right.
I see you are like an hour away from our flying field. We are having 2 flyins and one electric flyin this year. Here are the dates. Are field is wide open and big enough for anything. In sacramento, PA called the Aerobats flying club
June 11-12-fly anything flyin
June 18-Helicopter funfly
July 9-10-Electric only funfly
August 20-21-fly anything flyin