Aluminum Pan and Tilt Kit
Angelelec DIY Open Source Tilt/Pan Kit (5KG),Assembly for Horizontal Surface Mount Using two Servo Brackets. Perfect for Your Small Remote Piloted Robot Includes Hardware and two Ball Bearing Servos
These brackets can use most standard size Hitec analog or digital servos. So, beware if you are going to be using Futaba servos, there can be a bit of shimming that you may need to do to get this to line up correctly.
Further, here is a list of servos that is known to fit: HS-3xx, 4xx, 5xx, 6xx, 54xx, 56xx, and 59xx servos.
Servos from other manufacturers are not guaranteed to work but they are close enough that you can make them work.