I did exactly what you are talking about with the HVLP and brightsides on just the bottom of the hulls. Buy the right thinner from interlux (the name escapes me now) and follow their instructions for spray applications. The first coat should be just a light dusting, the second is where you get the color on, and any left over is just added protection. Priming is not essential(I didn't do it and it turned out fine, still fine after 7 months). Take your time on the sanding and prep and you will not regret it with the super smooth finish you'll get.

Hope this helps a little, andrew