We discussed this recently. The oil base paints aren't any better than the proffesional latex paints are since the EPA forced the good stuff out of the oil base paints. Go with a high quality proffesional grade latex paint, and you're right, two coats. Surface prep is a must. Remove all loose paint with a pressure washer, smooth out the rough areas, sand the gloss off, and prime any bare wood. If you have any dry wood, two or three brushings with boiled linseed oil allowed to dry helps a lot. For the metal grab irons & such, it's tough to beat Rustoleum or Krylon.