Water lines are easy. Pick a port located in a high pressure area like between the water pump and the thermo and plumb that to the lower water port on the turbo then plumb the top water port of the turbo to some port that has low pressure like something near the water pump inlet.

 

Water lines is one of the easiest things to ever do on a turbo miata. You literally unplug 2 lines and run them to the turbo. takes like 2 minutes