If you are determined to have a 4K 27" screen with great quality and excellent calibration software thrown in with the screen, look no further than the CS2740 Eizo monitor at £1300 all in ! Watch a few Youtube videos on the Eizo ColorNavigator 7 software and understand how well it works.
Your other more budget option is the BenQ SW271 at £950, it is about to be superseded by the BenQ SW271c , with the addition of a USB c connection and other as yet unstated upgrades. Though they list it a price is not available as yet, and Covid delays in factories might be to blame.
I don't know the mix of your usage, and can presume the choice of 4K is for Video usage , but having spent two weeks test driving a 32" 4K , I have to say that I feel it is overkill for stills alone, and made the personal decision to go 2k! The scaling at 27" with 4k is crazy ( around 200%) and Photoshops tool boxes can be an issue. 2K at 27" is lovely with almost no need for scaling and a detailed image . So add to your choices of screens to consider the Rolls Royce Eizo CG2730 at £1300 , or the budget BenQ SW270c 27" 2k for £676 with hood and calibration software.
I think the Eizo options will give you the better screen evenness of lighting , and the nicer calibration software , but the BenQ 27" 2K , with hood and Pallet Master calibration for £675 to your door from WEX is crazy money.
Oh, one final thought, if you are lucky to have a reasonable budget, go for the Eizo CS2740 and run it at either 2k or 4k if you need it . The screen has a pixel size of .155 as against the .233 of many of the 2k screens. Oh and as you are a youngster ( im a wrinkly) remember the Eizo's have a 5 year warranty and should last for years.