During the last beta my wife and I rolled sith. I took warrior she took inquisitor. I took synthweaving she took artifice.
Overall I found I could make gear for us that was just above our level and much better than the mission rewards. Not always but every now and then. The biggest benefit was that the armor you make has the right stats on them. Overall I provided maybe 45% of our armor. In any case it's helpful to be able to "plug the holes" in your gear. Most vendors don't like to sell chestpieces, and sometimes it takes a long time before you get to upgrade a particular item. Therefore a "meh" item you can make is better than what you already have.
With artifice my wife couldn't make lightsabers (granted we didn't get very far, just past Dromund Kaas), but the saber parts were invaluable. We got two lightsabers as drops and iirc one as a mission reward and thanks to the hilts, crystals etc she made I never had to change the original sabers I got when I became a marauder.
Both artifice and synthweaving are really useful skills for force users. I assume biochem will rock as well, but personally I would hesitate to pick cybertech on a Sith/Jedi. Maybe I'm wrong, hard to say at this stage.
This is exactly what my wife and I will be doing as well, down to who is playing what class even. She went so far as to create a chart to make sure we manage to get all of the Crew Skills properly handled among all of our characters.