Add Closed Cooling

[Claude]

Hello Jeff,
I not shure to be on the right place but it is a little difficult for me...
Here is the question:

I want to buy a Nautique 200 ski who run with a ZR 4 400 with 1500 hours. I want to run in salt water. 2 month by year...
The engine is not equiped with internal cooling system. so I would like to instal a kit. Some peaple says it is not possible...or just in separate pieces.
What do you think about, is it impossible...?
Thanks a lot,
Claude.

[Claude]

Last think, the boat use to run with gaz system, can it possible to create damage for the future with normal fuel?
Thaks, claude