Here is another tough mobile platform for your indoor and outdoor projects. The Dr. Robot Jaguar Lite Tracked Robot comes with WiFi, outdoor GPS, and 9 DOF IMU. It can handle slopes up to 45 degrees. The robot has a speed of 8.5km/hr.
The Jaguar Lite can handle stairs up to 180mm. It has high resolution video/audio, weather & water resistant enclosure, and a laser scanner. The robot can be controlled with a head mounted display and Gamepad. It comes with a SDK and sample codes.