Go for a 40-49" HDTV as:
Way cheaper than PC specific monitor with HDR comes with WCG + HDR as std.
Its still a little early to get a decent PC monitor with HDR that will in the near future be a big deal visually.
Or wait until January 2018 when new PC models with HDR are due to be announced (no-one knows how long to then hit the shops though its usually a few months after). There is no such thing as a perfect panel they all have pros & cons even OLED panels are not flawless by a long way. Do a lot of balanced research before buying something. Some PC gamers insist on it must have XYZ tech & moan about HDTV's which do not do more than 60Hz @ 4K but the tech is simply not there yet so for pro gamers or CG professionals you have to buy a proper PC monitor (around £3K for a decent colour accurate 4K model).
I bought one of these a few weeks ago it produces the most amazing picture to me for gaming, web use & watching movies on 4K UHD it makes movies look incredible especially 4k UHD
& I sit about 18" away from it
also does 120 Hz @ 1920x1080 but its a 4K screen so does 4096x2160 @ 60 Hz or 3840x2160 @ 60 Hz. Some people tried to tell me the text was poor or for PC gaming as it uses RGBW technology so must be no good as some pixels are shared
but so far its been flawless & produces the most incredible image on everything as well as being super slim (6cm!!), super bright & affordable (you can get for around £600 in sales going on right now John Lewis is best place to buy any HDTV from as they price match themselves & also give you back the difference if they sell for cheaper within 28 days). It cost me only £150 as I sold my old Phillips 4K monitor
only downside was I had to but an Active Display Port to HDMI cable convertor to get the full 0-255 colour range in Windows due to poor drivers from Nvidia do not report the correct colour level.
http://www.lg.com/uk/tvs/lg-49SJ800V