A few friends of mine like to have large 300 point games. I am wanting to build a 300 point Scum invasion. Any thoughts?

If you have the time to invest in a large game. Bring as many general ships as you can. Lots of cheap ships are usually better than highly specialized ships. Some broad ranging abilities can be very good as well, though I can't think of any on the scum side off the top of my head (maybe Torkhil, Manaroo, Serissu are useful)