I have no experience with gelcoat products, Dueceman, Joe, is the resident expert with very recent experience. Automotive finishes I am more comfortable with but from a DIY point of view, I have learned plenty from mistakes. Lately I have been using an online source, paintforcars, where I can get a complete base/clear kit for under $200. But there is so much more involved with the overall cost, compressor, dryer, guns, prepared space for application, lighting, etc. Lots of different technologies out there including brush and rolled. Paying outside labor is expensive, but when you complete your first finish with good results, you will understand the amount of work involved. I would estimate painting a two color 16' boat with no flake around $2000-2500 from a reputable shop. DIY projects such as this can be either rewarding or heartbreaking. Research can go along way towards your decision, plenty of info from folks on this site as well as videos on the net. Good luck, Michael.