@nyakojiru The RK3588 and RK3566 are fantastic SOCs. At least 4GB RAM. An eMMC is much more reliable for the boot volume than a microSD card.
This won’t be able to do any live transcoding, so make sure your clients are configured for direct streaming.
You can get fairly large USB 3 flash drives and microSD cards for compact local storage. A NAS is better than local storage for a media server, though.
@willya I’ve done that in the past. It works ok. I bring an Apple TV to use as the client. I like the tvOS Plex app quite a bit and I don’t have to use VNC or get up to control it.