I know you said you have given up, but I wanted to post this for those still looking. I use a Snuggle Up Bird Warmer. It attaches to the cage bars near a perch. The cord is on the outside and I have it plugged into a surge protector to help prevent shorts. With this method, they can sit on the perch and get as close to or away from the heat as needed.
http://www.drsfostersmith.com/product/p ... atid=26388






