What monitor should I be looking at getting ?

[TurtlesWithGunz]

I've heard that 4k is amazing but I can't decide between 4k vs high refresh rates.
Anyone got recommendations on monitors I should look at ? Budget is around 700USD. Looking to buy one on Cyber Monday
Been looking at the Acer Predator XB271HU 27" and the Philips BDM4350UC/75 43" 4K UHD IPS Monitor.

My PC specs :
CPU: i7-6700k overclocked 4.4ghz
GPU : GTX 980Ti 6GB SLI G1 Gaming Version PCI-E 3.0 16X Video card , 2816 CUDA ,1291 MHz, Triple Cooling
Mobo : Gigabyte Z170X-Gaming 5 ATX Intel Z170 Chipset for LGA1151,ATX Form,4x DDR4 DIMM,Display Port/HDMI,M.2 Socket connector,Killer E2201 Lan,SATA3,USB3,USB3.1,USB Type-C,Support for 3-Way/2-Way
Memory : 32GB DDR4
PSU : Cooler Master 1000W
SSD : 500GB
Storage : 2TB

 

[banker]

it matters what you want looks or performance, I play with a gtx 1070 on 1080p and I honestly like 1080p