To start, i have a highwing.

I want to make a custom water-cooled system to keep the engines cooler. My question is as followed:
1. Does it matter where i drill the hole on the bottom of the boat?
2. How high in the back(transon) area should i have the outlet going?
3. What size tubing should i use, i would like it for cooling, and for water shooting pretty far back..

Any other tips or suggestments would be awesome.
Thanks!