@hellogoodbye

for best quality, most of the top tracker groups don't use HEVC, cause it's inferior to AVC and destroys compatibility.
best encodes are on HDB, AHD, PTP (well most good encodes are coming from HDB and AHD to PTP, but they have some good encodeers too)

if you like HEVC and have a decent PC with connected 4k TV i would just go for UHD remuxes.
besides HDB, AHD - BHD, PHD, and HDT offer constantly new UHD remuxes, or go for web HEVC.

UHD rocks, and currently is the only format worth to have for HEVC, for encodes it doesn't save much or even has larger sizes if you want details.
most UHDs already have small compressed video streams and thanks to 10bit and the internal filters of HEVC encoders - banding, blocking isn't much a problem anymore.

while i saw a few UHD to 1080p releases recently, but file sizes are huge, i would just go for UHD remux if you have 4k TV