Here is another rig that lets you master overhead shots. The Glide Gear OH 75 Overhead Pole Rig secures a pole to your light stands, so you can attach a camera to take your shot. It comes with 2 x 1/4″-20 accessory threads, pole clamps, and baby pin posts.
The OH 75 can be mounted onto tripods too. It lets you attach articulating arms and other accessories in addition to your camera.