Adafruit (Out of stock)
https://www.adafruit.com/products/3410
pimoroni (Only 1 per customer)
https://shop.pimoroni.com/products/raspberry-pi-zero-w
The Pi Hut (Only 1 per customer)
https://thepihut.com/collections/raspberry-pi-zero/products/raspberry-pi-zero-w
Aliexpress (No extra bit, bare bones)
Who else can I try?