You can't play a Sith Jedi - you're either a sith or a jedi. (DS/LS have nothing to do with either). It's like saying you can play a Republic Imperial. (Hmmmm, I'm gonna run for President and tell everyone I'm a Democratic Republican....)
And BW has already stated you'll never be able to play a race that can't speak Basic. (so no Wookies, no Jawas, no Trandoshan.