Quantity   Component name
1 × Chassis kit https://smile.amazon.com/gp/product/B01CXVA6IO/
2 × HC-SR04 pack with mounting brackets https://smile.amazon.com/gp/product/B01JG09DCK/ (two to get three mounting brackets)
1 × Adafruit Motor Controller Shield https://www.adafruit.com/product/1438
1 × Sparkfun Blackboard Rev C https://www.sparkfun.com/products/15296