is there custom galaxys like star wars

It is entirely possible, but the races would all be the same. You could make a mod to turn a bunch of the minor races into the populations of the more important planets from your favorite franchise (i.e. Turning the Paulos into the Huts, or the Scottlinga into the Tatooine.. eans   )

I don't know of any maps/galaxies available for download like the ones you mentioned, but their are Total Conversions for Star Trek and Star Wars (I think there is a Star Wars mod) which would concievably include a custom galaxy for the relevant franchise.

As a simple alternative, find a listing with all the planet names from the series you want and replace the stars.txt file. When you start a new game, these names should be used. Of course, the starting planet for the races are defined in the race-configs.