There are a great many variables, and many viable build options. 

This is NOT A "WHAT TO BUY" LIST, but some generalizations to help you start off going in the right direction

First off, for all current EVGA factory watercooled cards, we recommend a a minimum os a 2x120 radiator, as the single 120's will not have sufficient thermal dissipation to cool a current EVGA Graphics card.

Next, while the cards do come with 3/8 inch hose barbs to accomodate certain loop configurations, we highly recommend using 1/2inch Inside Diameter tubing, as it will provide superior flow and not restrict the abilities of the cooling system.

Please make sure to balance your fan type with the radiator you choose, some radiators work better with very high CFM fans and others are optomized for medium to low CFM fans.  There is alot of mention of push/pull configs, while it will help with static pressure, it is not necessary.  However, unless your case will not accomodate this, it is advise for a 1 sided fan solution, to run the fans in a pushing configuration rather than pulling.

As a general rule, you want your loop to be organized like this Reservior - Pump - Radiator - Device(s) you are cooling - back to Reservior.  These can be expanded greatly

If there are ever any questions, please post them in our forum, along with the full composition of the water loop.  https://www.evga.com/forums/tt.aspx?forumid=37&p=1