For the electrical components, Digi-Key[1] and Mouser are the two go-to’s. I didn’t read 100% of everything, but unless he’s selling the PCB’s you’ll have to get them fabricated from the Gerber files in the repo. JLC is the go-to for this - expect to pay $5-$10 for a single-sided design like this, and you’ll probably get free shipping if it’s your first order.

1: ADuM1201 - https://www.digikey.com/en/products/base-product/analog-devi...