I've only seen one episode, but he doesn't seem to need to kill to survive in this. It's more like an addiction!
And as shit as it would be fighting an addiction which never goes away, I'm still going to go for a vampire for the coolness factor.
Ghost would just be too lonely if all your social group went away.
However, if I could be a werewolf like Sergent Angua is in the Terry Pratchett books (i.e. having total control of your inner wolf and being able to track people), I'd pick that.