my friend and i are going to co-op the repubic storyline were pretty excited about it. hes going to be playing a jedi guardian so my question is which class do you think would best compliment a guardian? thinking about a trooper but not sure ive played mostly on the empire side so the republic storyline and classes arent as familiar to me. looking for some solid advice to make this republic run as smooth and kickass as possible

The best would probably be a sage/shadow as you can level through tython together. Also guardian/sage combos are just good.