What box – video AND hi-res audio?

Hi all,
Brand new here, so hope I’m not asking something that’s been answered a millions time already (I did a quick search).
My current set-up is all my media is stored on general use PC, which is connected via ethernet through the house to the living room which has the TV and hi-fi system. I’ve been using PLEX on my Samsung TV (D8000 plasma) for years to play video files from the PC with mostly trouble-free operation until recently I’m getting constant buffering. Nothing in the system or network has changed, speeds all report as OK.
Music is streamed from the PC to a Logitech Squeezebox Touch, connected then to an external DAC > amplifier > speakers.

With the recent issues with PLEX and the Squeezebox starting to show it’s age, what I’d like to do is get a foolproof box that will easily stream media in the same way; as an intermediate between my PC and TV/hi-fi. Easy right, hundreds of solutions out there.
The problem seems to be my need for a great music server. All android boxes limit output to 16bit/48kHz Sad As a MINIMUM I need the ability to play raw 24bit/192kHz FLAC, via USB output would be ideal but would settle for coaxial.
Even better would be the ability to play/stream DSD files!

I was set on the Xiaomi Mi Box but then read it had a (very) locked bootloader, so no chance to run LibreELEC on it (or anything else; volumio, jriver, etc).
Any obvious choices out there for what I want? HiMedia Q5 Pro (a wee bit pricey), something else?

No need for 3D video playback, no immediate need for 4K playback although it will definitely come in handy in a year or two. Netflix is not a current requirement, but again, would come in handy soon enough.
Vast majority of my video media is H264/mp4, but a few MKVs, too.

Cheers all, hopefully someone has a solution for me.