Home custom build NAS help

[jonig]

I want a NAS that will be capable of the following:

• Perform backups of PC, phone... (encrypted)
• Act as a Plex media server (a single 4K Blu-ray quality video stream with no transcoding)
• Act as a BitTorrent client

As the video files I want to stream have a high bitrate, I first thought about the Synology DS720+ which has a 4 core Intel Celeron J4125 which I'm sure it's powerfull enough. However, as it costs around 480 EUR, I'm considering a custom build NAS for that price and run Unraid on it (because of the increased performance and modularity). My budget is around 500 EUR, drives not included (which are going to be 2x 4TB HDD) and Unraid license also not included.

 

Is the custom build approach worth it for my use cases? If yes, I'm really lost on which pc parts I would have to pick. Could I have some orientation or any NAS build example for my purpose?

Thanks.