Geeekpi Raspberry Pi 4 Dual fan heatsink case for just £11
The case supplied in the Raspberyy Pi 4 kit was basic and didn't include ribbon cable slots, I also noted the Pi ran quite warm.
This new case solved both problems.
Supplied with all parts you need.
Just make sure you get the thermal pads in the right places.
https://amzn.to/3N0CVJy