https://www.techpowerup.com/256591/silverstone-unveils-cs381-chassis-for-diy-nas-creation-rigs The very 1st prototype of this chassis was shown way back in Computex 2018. Now the latest finish model is ready. The CS381 has room for a micro-ATX motherboard with room for a full-height graphics card, but a CPU cooler only as tall as 6 cm, which is plenty of room for the pump-block of an AIO CLC. You can use a CLC with a 240 mm x 120 mm radiator thanks to the two 120 mm rear exhausts. An SFX/SFX-L power-supply bay allows you to deploy a reasonably powerful PSU. Two additional 120 mm fans can be mounted along the sides. Front-panel connectivity includes two USB 3.0 ports, and HDA jacks. The company didn't reveal pricing.
Personally I find this to be an outstanding design of a DIY NAS that you can build and adapt to your needs.