Parts list

AdirPro Measuring Wheel. Sources: TigerSupplies | TigerSupplies via Amazon
Raspberry Pi Zero W sources: PiShop
JST PH 4-wire connector Part# S4B-PH-K-S sources: DigiKey | SparkFun (can also be purchased from a local hobby shop)
USB A to micro USB cable (This is a common cable for charging phones and other devices. If you already have one, you can use that; there's no need to buy another) sources: PiShop | Amazon
32GB MicroSD Card + Adapter (Be careful of counterfeit SD cards) sources: PiShop | Amazon
Portable battery pack with USB two USB ports (one for the Pi and one for your phone, if you already have a USB battery pack for your pone, no need to buy another) sources: PiShop | Amazon
3D printed case to contain the Pi and replace the handle parts that were removed. (If you do not have access to a 3D printer, you could DIY some padding for the Pi with duct tape, bubble wrap, etc)

Optional:

SD card reader (if you already have a SD card reader built into your laptop, it should work fine with the SD to MicroSD adapter that comes with most cards)