As long as this is a 1440p monitor at 60 Hz, DVI, HDMI and DisplayPort are all fine and I don't think there would be any difference in image quality. If you have to pick a cable to buy, just grab DisplayPort as its the newest and best standard. But if you'd rather just grab whatever's cheapest, I don't think you'd ever notice a difference.
However, if your monitor is 1440p @ 120+ Hz, DisplayPort may be required. DVI only supports up to 1440p at 60 Hz, and I'm unsure about HDMI.