Can anyone recommend a good 27" Korean 2560 X 1440 monitor for use with my 2011 iMac?

happy new year!

according to my 2011 27" iMac specs, I should be able to connect a 27" 2560x1440 monitor as a second screen to my 2011 27" iMac. I hear that the best values are found in the korean monitor market via eBay, where prices are about $220.

can anyone recommend a good brand and or model that they have purchased for use with their Mac? I saw a couple listings where they said not to use with a Mac for best compatibility and it put me off a bit.

THanks!