Does a Titan X need watercooling? Im sceptical towards the nVidia cooler. Sli would not be out of the picture on a later date when one wont do it annymore.
As long as you have good airflow in your case you should be fine. The stock cooler does a good job .
Water cooling will make the system quieter if done properly.
Have you got a Titan x or looking to buy one ?