With the provision that this could change for the English version - here you go (but I have some additional, personal, comments regarding this too on why this isn't really relevant). There's a light freighter (Scarab) that has a crew of 4 (minimum 2), an attack ship (Azuk) with a crew of 5 (minimum 2), a courier ship (Oryx) with a crew of 3 (minimum 2) and a salvage ship (Kamruk) with a crew of 4 (minimum 2). The first three are Class III-type ships and the last one is a Class IV-type ship. Technically speaking there's no real difference between courier ship and an attack ship, they're both Class III - the difference is in how you configure them.
HOWEVER! These listings are for specific configurations of each of these models (as I said the first three are all Class III, which is the important bit). Your ship can be customized with modules (the number of modules depends on the Class you pick), such as extra passenger compartments to hold more people, and the combat system uses 5 different roles for characters to fill so the number of crew members can and will depend on how you configure your ship. No weapons? No need for a gunner (though that sounds suicidal). Two weapons? Might as well have two gunners so we can fire twice in a round. Just four characters in the group? Ok, let one of them act as captain as well as whatever other role is suitable. The rules allow all this and as I (think I) mentioned in the other thread you can have a ship AI (or more) that fulfills one (or more) of the roles.
So the way I look at it is, let your group decide which ship suits them best (ie. coolest...) and make it work from there. The great thing, to me, is that you (and your group) really create your own ship from scratch using a generic Class value (though the higher the Class the more expensive it is and the more in debt you start...). Want a courier-like ship? Ok, maybe go light on weapons and cargo space while you increase maneuverability or such. Want an attack ship? Focus on adding weapons. Or just pick the options and modules you think you as a group will have the greatest need for and cobble together some weird hybrid ship.
P.S. Just to clarify: Class is a size measurement of ships and not to be confused with ship classes from, for example, Star Wars where X-wing is one class, TIE/ln another and YT-1300 a third.