Would either of these 4K TV's work as a PC monitor?

[JayBobGamerZz]

So I've been looking around for a 4K monitor second hand (I can't afford new).
I just came across several TV's on Trade Me (basically New Zealand's version of eBay), and because they're were so cheap ($500 NZD, so about $360 in USD for the 50") I was considering getting one.
They are Samsung JU6400 models, a 40" model and a 50" model - so I did a bit of research to see how they'd fair if I were to game on it with my PC and PS4 Pro but haven't found much.
I'm especially curious about the refresh rates, are they 60hz? I've found someone saying all Samsung Series 6 4k TV's are 60hz - is this true? The 50" (UA50JU6400KXZN) has a clear motion rate of 200, whilst the 40" (UA40JU6400) has a clear motion rate of 100, which makes me rather confused as they're both JU6400 models but have different refresh rates.

Would either of these two screens work as a PC monitor/also for PS4 Pro? I'll also note that I'm not interested in HDR, it's too expensive for me.

Thanks

 

[boosted1g]

Work as a monitor: of course
Work well for PC gaming: no.

TVs are designed to show fast motion stills of images from quite a few feet away.
Monitors are designed for digital renderings at close distances.

Also, if your GPU is not HDMI 2.0 compliant then you will be crippled to 30hz from your PC.

 

[Eximo]

This place has the most comprehensive TV's for gaming reviews.

http://www.rtings.com/tv/reviews/samsung/ju6400

7.9 isn't a bad score, same as my older 4K Vizio 60" (Though I don't game on mine, didn't really enjoy the living room experience)