This is a very old thread. Grave-digging isn't technically against the rules, it's just unwise and can be annoying or provide you information that is obsolete or unhelpful.
Not all ship models have cargo pod slots. Some do. Examples of ships that do are the generic trains, the Stork, the Crane, and the Heron. If you want details on which do... maybe you can play around with different ships in single player! The Wiki might otherwise have some (also outdated) information.