If the gelcoat isn't bad other than dull and chalky, you might just try polishing compound. Start with a small area (transom?) and see what happens. There are all kinds of people out there repainting hulls at varying prices; check at the boatyards and marinas in your area. A good job is labor intensive, as the prep work is what makes the paint job, and consequently will drive up the cost. Also, most paints used in this application won't take wax or polish (at least it's not recommended by some manufacturers) and so once you paint there's no going back. Hope this helps.