Thanks for the update John, Guess I'm showing my age, However please correct me if I'm wrong but I don't think such a expensive item is needed for kayaks as you need for a guitar or any other fine instrument? Just my thoughts. Nick R.

Nick-
You may well be right.
One thing to keep in mind, though - on a guitar you always hand (fine sand and) rub out and polish the finish after spraying, or hand sand and use a buffing wheel.
On a car, it's the same- hand or machine work after spraying.
So a bit of orange peel or dust isn't a big deal.
When I spray paint or clear coat (like Interlux 'Perfection') on a kayak, I want it to look 'good enough', as I don't want to hand finish something boat-sized. Anyway, though clear coat will stand up to sanding and rubbing out, some of the 2-part finishes I've used don't- they are designed to spray to a finish standard.

Try a cheap gun and the air setup on hand - it's only a small amount of money for experiments. If the results are OK, you are set to go.

When I started paying a lot of money for the finish products, I resented having half of it end up on the walls of the spray booth, and I got a better gun.

That's the benefit of having a hobby, not a business - there's no need for logic in our purchases! We don't need to 'prove we need' that expensive spray gun or hand plane!