I'd suggest going the first option suggested by sevt_chevelle: i.e. base and a flat clear. That is unless you're pretty confident in your painting ability.

Unlike a gloss that you can buff to make look good hiding the imperfections a single stage satin to me was one of the hardest paints I've ever sprayed. I used an Omni pre-flattened that I can probably still find the source for if you want.