My Rover project. I used a Tamiya tank as the basis. You could make this rover by just acquiring the dual drive motor and replacement tracks/axles and wheels:

Replacement Track and Wheels with axles: https://www.amazon.com/Tamiya-Track-Wheel-Set-70100/dp/B001VZJDY2/ref=sr_1_1?ie=UTF8&qid=1537656093&sr=8-1&keywords=tamiya+tank+tread

Dual drive motors: https://www.amazon.com/gp/product/B001Q13BIU/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

Thunderborg motor controller: https://www.piborg.org/motor-control-1135/thunderborg

Raspberry Pi Zero: https://www.amazon.com/gp/product/B0748MPQT4/ref=ox_sc_saved_title_1?smid=AHALS71WJO58T&psc=1

Lasty, repurpose a bluetooth PS3 controller or buy one used on Amazon. If you get a real Sony controller, life will be fairly easy following the tutorials on PiBorg's website.

I also have a git repository for the tank code that I run: https://github.com/gcoltharp/rpi_tank_rev2

Project demo video: https://youtu.be/5_bZUG1xI1I