I created this case for a Pi 4 (with POE HAT), a 2.5' Hard Drive and a SATA to USB adapter. There is a slot on the IO side of the case that can be used to store the excess cable for the SATA to USB adapter which makes this case slightly unique.

The case is designed to be cooled passively which is why the side panel and top are mostly open but there is space for a 40mm fan above the Pi. Depending on your budget, I'd recommend using one of these (https://www.amazon.co.uk/Noctua-NF-A4x10-5V-3-Pin-Premium/dp/B00NEMGCIA) or these (https://www.amazon.co.uk/GeeekPi-Raspberry-40x40x10mm-Brushless-Cooling/dp/B07X93XGBD/).

You'll need:

• 4 x M3 x 8mm screws to mount the HDD/SSD to the case
• 3 x M3 x 8mm screws to attach the side panel
• 4 x 12mm M2.5 screws with nuts to mount the Pi
• (Optionally) 4 x rubber pads/feet like this https://www.amazon.co.uk/Adhesive-Coasters-Dampening-Furniture-Protectors/dp/B08TRBQPXG/