[noggin]

The Best Of - categorised - media players on the market (click)

Personally I would try LibreELEC in a x86_64 Intel i5 first. LE can even be run entirely from a USB stick, completely seperate from the existing OS:
https://nucblog.net/2016/11/installing-l...intel-nuc/

An i5 should easily be able to CPU software decode H265 (HEVC) content:

https://wiki.libreelec.tv/installation

4K HEVC, which will mostly be 10bit will need HEVC hardware decoding.
Note you are REALLY limited in your hardware choices if you want 1080p 3D support.

 However whilst those solutions will play UHD HEVC/h.265 content with hardware acceleration - they won't playback HDR content in HDR (Windows solutions may do if the NUC is a recent model).  

I think the OP meant to type HDR10+ (not HD10+) so their set - like pretty much every UHD set now sold - is HDR compatible.  Given that a lot of 4K/UHD HEVC/h.265 content is now HDR - you will be limited to LibreElec's 8-bit SDR output on Intel - and an HDR->SDR conversion?

Wouldn't something like a Vero 4K+ with OSMC be a better bet?