some auto parts places like Napa have kits, degreasers,primers,sealers and top coats all in one. that way your asured that all the components are compatible.
I just painted mine with duplicolor paint shop system. I got it at Advance Auto Parts for about 60 bucks. They have the primer, color coat, and the clear coat
Any auto part store should work, but I would pay the extra for epoxy primer and a fiberglass paint. It won't peel off and can take the vibrations without cracking.
The Medalist has a steel body, sand, prime and paint just like a car.
Any automotive paint will work.
For a super job, clear coat and power buff to a mirror finish.