Share 'Topside Paint?'

I know we discussed bottom paint in depth but I am about to paint everything above the waterline and would like to know what kind of paint others have used and how they went about applying it.  I have the original paint mostly sanded off and imagine I need to start with some sort of primer.  Is gelcoat difficult to apply or expensive?  What about non-skid on deck?  Thanks in advance for your insi…