I have a small selection of ships, mostly imperial but also few some scum ships that I am willing to part with for cheap or trade. Also have the rules and movement templates, dice, etc. Send me a message if you are interested.
Not sure about an alternate starter box for scum. But I do know that there are no limits to ships other than named characters are unique. That said you can take the named character in a Quadjumper and a generic Quadjumper in the same list. So its really limit to the cards rather than the ships.