Currently using HTPC for 4k HDR TV
For 4k HDR playback at minimum, use GPU with 4GB of RAM, so minimum NVIDIA model is the GTX-1050ti.
As for the software for playback, I used the Kodi or MPC-HC & add-on codecs I read from AVSForum (LAV, MadVR etc) & lastly "Movies & TV" from Win10 pro. 1080p movies looked pristine on either of these media players. My preference is the MPC-HC.
Btw its a lot cheaper if you go the NMT route. I also used Minix U9-H.. 1080p movies on Kodi ayos din.
Tama si Boss Stagea, if gagamitan mo na ng "shaders" post processing, laggy na ung HTPC ko, the CPU reaches 100% utilization.