Your choice is really up to you. A screw drive is generally quieter than a chain drive. The important thing is to purchase an opener with enough horsepower to lift your door. For a 16 foot door, if made of lightweight material, the manufactures claim a 1/3 hp motor is sufficient. I would recommend a 1/2 hp motor for a 16 ft door. It only cost a few dollars more and will last a long time. If your door is heavy (coats of paint add tremendous weight to a door) look for a larger motor.