IMHO
I just sticked with the paint and varnish as suggested by CLC. I have done a fair share of finishing and painting over the decades. I found the Interlux Brightside paint to be very smooth and easy to apply. So far the finish seems tough to the touch. By that I mean it is not brittle nor flaky. The paint is meant for marine applications so I feel pretty confident in suggesting it. The Varnish by Interlux is little bit more touchy to apply. It has a viscosity that I found a little to thick. I added about 5 to 10 percent of the thinner they make. And once you open the can, be ready to use it. There is a very short partial can shelf life.
If you don’t have a lot of paint practice, try I few test runs first on say the cut outs of the windows or the vent. You don’t want to be leaning how to do the roll and tip method on the fly. See the boat building video series on the CLC web site for a video of the painting and finishing techniques.
Timing wise I would wait until ALL or most of the drilling, sanding and fiddling is done. (mostly sanding) You don’t want dust to spoil your finish. At least make sure you have a warm, clean and well vented space.
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I only need 2 quart cans of the varnish – 3 coats of outside, galley and bulkhead. (I would think most people use three)
I used about half a quart of the Primer for the bottom – 1 coat. I am old school and ALWAYS use a primer on ALL pf my painting.
I used almost all of a quart can of Black Brightside – 2 coats.