Here is another quadruped walking robot with everything you need to get started in coding robots. The Lynxmotion SQ3U robot comes with SSC-32 servo controller and the BotBoarduino microcontroller. It has 3DOF per leg and uses 4 HS-645MG servos and four HS-422 servos.
The robot is 6″ high and 9.5″ wide when standing. You also get a Ni-MH 2800mAh battery pack.