What bit to use to get my horses head down?

So i am using a kimberwick on my 7 Year old paint. When i bought him the previous owner told me the name of a bit she used occasionally to keep his head down. I wrote it down but i cant find the piece of paper. He is very high spirited and stubourn. I am working really hard to get him to listen how he used to. He is very testy and certain things tip him off. I try to be gentle on his mouth and lose my legs but lately he has been a bit testy and i need to pull hard to get him to stop. Its been a bit rough because he puts his head all the way up. My trainer had me on draw reigns but i really really hate those. So anyone know what kind of bit or what i can do that may help?