What are you looking for? You've not clarified - Is your goal to have a bunch of components like Kerbal Space Program? If so, can you supply the specific details of how the components are connected? Building 3D elements that connect together is not simple, and really requires a clear understanding of the underlying code that connects the components.
Have you established consistent connections between components? If I wanted to add a thruster to a command module is there a way to do that? Can I instead connect a cargo module to that same location?
Not wanting to sound negative, but the brief is really vague and as a 3D artist I'm a bit baffled about what you're trying to accomplish.
If you can more clearly explain what you're trying to accomplish then that would be good. At present your goals are unclear and, as a consequence, unachievable.
Nick