So you would like to build your own robot tank with Arduino? The Kesoto Metal Robot Tank Platform has you covered. It has a steel construction and can achieve a speed of 1.2m/s. It has rubber tracks and dual DC 24v motors. This tank can carry 15kg load.
You can use this platform to build your own advanced Arduino & Raspberry Pi robots. The entire body weighs 10kg. It can climb slopes up to 35 degrees.