Update and question.
I have bought the Eizo ColorEdge CS2731 27" 2k monitor and after some delays it arrived today. I already love it, although it's a beast! I come from a 23" NEC and to go to 27" is well, rather intimidating... 
For a while it will have to work with my old 2009 Mac Pro. Now the Mac has one DVI Double Link port and one Mini Displayport on board. The monitor also has a DVI port, so I used the DVI connection and got the monitor working immediately. However, it looks like this:
1/60 • f/1.8 • ISO 200
Image hosted by forum (
1168605)
© Levina de Ruijter [SHARE LINK] THIS IS A LOW QUALITY PREVIEW. Please log in to see the good quality stuff. It's a crappy iPhone pic because a screenshot didn't work as that looked the way it should, so apparently the Mac thinks nothing is wrong and indeed, I've checked System Preferences and the Mac sees the screen. It's listed and the 2K res selected, so it seems there's nothing wrong on that end.
I'm going to get a Mini Displayport to Displayport cable as I think that would be a better connection, but I need to know which one I need exactly, because there seem to be different ones (1.1, 1.2, 1.4)? Or maybe I have overlooked something? But I have to do something quick because now I am sitting behind my beautiful new 27" screen scaled down to 1920x1080.

Although text is nice and big, it's not quite what I had in mind.

Thanks for any help!