Buy an IPS panel with a decent SRGB profile and a spider to calibrate the monitor. What you will find is that the screen on the max may look great because you don’t have anything that is genuinely correct to compare it to. If the screen is miles off of the Mac colouration does it matter if it’s perfect? Not really no. My concern at that point would be the Mac and from there I would be conscious to make sure any final grading was done on the screen at home before finalising work.
As for what works.
Eizo, benq, iiyama.
Expensive to cheaper.
I personally use an Benq SW271. It costs about £1k but is a be all and end all monitor.
ILM use eizo (the people behind star wars) and some of the entry 24” 1080p jobbies are 100% sRGB which is the important bit (same standard as the net, most printing companies use that space too rather than adobe rgb) and they can be had for about £250 and up wards.
The questions you need to ask yourself are as follows.
What size do you need? 24 / 24 / 27 / 32
Resolution 1080p / 1440p / 2160p
Inputs ie DP, miniDP, HDMI ????
Budget £300
So with that in mind your looking at above in bold as a solid performer and the above in italics as possible but risky or outside of budget. The underlined is outside of budget potentially but may be worth the extra to dip in to.
My recommendation would come in with the following.
24”
Eizo CS230 - £400ish 1080p - Pro grade
Eizo EV2450 - £250ish 1080p - ametuer grade
Dell P2415Q - £350ish 2160p - ametuer grade
27”
Benq SW2700PT - £550ish 1440p - Pro grade
Dell U2717D - £370ish 1440p - ametuer grade
Out of all those the CS230 and SW2700PT are the best two units.
The cheaper Eizo is likely a better unit than either of the Dells but the Dells do offer good value for money with the 27” and if you like to pixel peep and need the sharpness you get with your Mac, the 24” 2160p will probably do a good job of keeping colour reasonably accurate and you happy as the resolution gives the perception of better quality even if it isn’t.