What size gaming monitor would you like or require?
What is your budget?
Look at the recommended hardware specs for the games you wish to play.
Since you already have "committed" to a GPU you must find gaming monitors that will work with that GPU.
Read the monitor's specs. Then read reviews about those monitors. Visit the manufacturer's websites.
Read the monitors' User Guides/Manuals. Check their manufacturers' forums. Look for what is said as well as what is not said. What do people like, what do people not like, what questions are being asked, are those questions truly being answered?