You could use rpilocator. This website tracks the stock of official Raspberry Pi distributors. Follow them on Twitter and enable push notifications. You will be notified as soon as the bot tweets that products are in stock.

Recommended hardware:

• Min. 4 GB of RAM.
• Min. 32 GB of eMMC flash space.
• If you opt for the CM4 or CM5 Lite: as the Lite variant does not have an eMMC module, you must use an NVMe SSD hard drive.
  • Some users reported that these SSDs are not working on the Home Assistant Yellow.

Related topics

• rpilocator
• SSDs that have been reported to not work on the Home Assistant Yellow