What all will it need for it to be operational?

what size boat you putting it in?

As far as the "extras" buy yourself a pump to cycle water, the rest you can do yourself, easy to do....

It's a 82 Excalibur hawk 40. Back in the day it had some sort of ac unit in it but it has been long gone. All the hoses for the cabin vents are still there...... i have 3 vent hoses in the rear that connects 6 vents so I will need some sort of "joiner" so the air coming out can branch off 3 different ways.

gonna need minimal of 8-9000 BTU.... 10-12,000 would be best....

Mine is a 7000 in a 35 Cigarette, perfect for mine and cabin not that big, boat is white also, if you have dark colors for sure need much more... just FYI

Damn ok

Where can I get one at reasonable price? Do they sell used ones anywhere?

sorry, didn't wanna see you buy one WAY too small...

Here, Ebay... boat salvage yards... I got mine from a cruiser local salvage yard for 300.00

My boat is white also.