C Dory owners have used many different ways from fold up suit case panels, thru the flexible to the solid screwed down on the cabin top. There needs to be an air space under the panels. At least 200 watts is desirable if running any refrigeration.
Do you cruise long distance and time without any mains power or generator? If so then solar panels make sense. We never put them on the boat, instead carried one of the Honda Generators, 1000 or 2200.
Do you want to track the sun? or just lay flat and take a chance on how much you will need. Every boat with solar panels should be tracking battery state of charge, with device such as Victron Smart Shunt or 712 monitor. You want to measure volts, amps in and out, and state of charge.
Consider the latitude and potential cloud shading, Ambient temperatures are important. Type and size of battery and the controller is important. Some of the cheaper LiFePO4 are now competitive price wise with quality AMG batteries.