I'm no expert but from my few experiences with powder coated Jeep parts,
#1 Sanding will definitely be key. Enough to create slight texture but don't destroy the thing.
#2 Spray both primer and paint in very, very light coats as it will be twice as easy to make a drip appear. Again, refer back to #1.
I don't know if you need auto-shop paint but it certainly won't hurt. As always, the true experts should be along shortly.
P.S.
Not applicable but if you ever need to cover rust. Blue steel is an awesome product. Sand only enough to create texture as it actually needs the rust to bond. Goes on blue and dries black but will not give a nice finish for your needs.
