I got a 144hz monitor : http://www.amazon.co.uk/Asus-VG248QE-24-inch-LED-Monitor/dp/B00B19T7QC
I would recommend you get one with an IPS panel, although this will increase the price, otherwise the colors aren't as good as normal monitors, and you would have to do some magic with the color profile settings.
If you dont care about the colors that much then just get one with a TN panel (like mine or above)