During the time when training to get from Apprentice to Knight, people already get attached to their characters. I would heavily recommend you to either RP on with your character until a chance like this randomly pops out or make the Sith character yourself. Because of attachment.
I have one more recommendation: sudden forced, artificial kills are not good. Participate in invasions, have duels, do skirmishes, whatever. Some time there will be the time when a character may die in your one's hands. This way, you earn honour. Artificial kills rarely make others see you as honourable. Maybe ICly, yes, but not OOCly.