Update:
Actually I changed my mind and I am interested in Getting a PlayStation Pro - 4K on the Pro will apply temporal filtering like the option in Rainbow Siege. 4k = 3840 × 2160 = 8,294,400 pixels divided by 2 = 4,147,200 pixels and it will apply 2x MSAA. 2560×1440 = 3,686,400 pixels. Technically the output is 4K but it is output of 4,147,200 pixels with 2x MSAA which is a vast improvement over 1080p pixels count ( 1920 × 1080 = 2,073,600 pixels) or ((4,147,200 - 2,073,600)) / 2,073,600 = 1 × 100% = 100 % increase in pixels count over the regular 1080p.
2nd - I will be Getting a new television set and after reading a lot of reviews , I will be picking the Sony X800D , which is recommended by Rtings (
http://www.rtings.com/tv/reviews/by-usage/hdr-gaming/best) as best affordable TV set for 4k HDR Gaming , knowing the addition of HDR @ 4K will increases input lag , and this model in particular registered about 30ms in 4k HDR , plus it has a true 10 bit panel - x800D features a wide color gamut. It covers almost all of the P3 space, which is great. When watching HDR content, colors are rich.
Overall it will be a great combination , + it has 4 HDMI two of them supports 4 K and HDR as such I will link the PC and PS4 Pro to it.