The sayins are named after vegetables so Latice {Lettice} and Kolace, just cos I like the name. What theme are you using for the villians? I suggest the moons of Jupiter, cos there's so many of them.... just don't choose ganymede....
Now as for more Names.. Lets see DemonSayajin...... Spirit Sayajin. EpsilonSayajin NovaSayajin....