Check local sources. Your desire to have a turkey that doesn't exceed 20 lbs. needs to be clarified as to whether this is a live weight or a processed weight. Any of the heritage varieties will have males that dress out around 20 lbs.I'm actually not picky. I'd like something that can live for quite a few years and not exceed about 20 lbs. Doesn't have to be show quality or anything, I just don't know where to start looking.
All of the hens of heritage varieties will be under 20 lbs.