I helped my friend paint his airplane. We primed with UV Smooth Prime,
applying enough coats to adequately fill minor imperfections after sanding.
The primer cured for months in a mostly dry climate while he worked on other
parts of the airplane. For the final paint, we first sprayed an Imron
sealer coat, followed by Imron (2000?), a single stage top coat.

He's been flying for a few years and the paint has held up fine. He won an
award at Oshkosh.

Good luck,
Dennis Johnson