Yoda

It is a slower build, but I think you should go with Luminara, QGJ, Barriss, Ahsoka, and Obi-Wan. You don't really hear anyone regretting having those Jedi up to 7* like you do with Eeth Koth, Mace, or JC. Plus, the first four will form a GW team that will all but guarantee you complete it every day. But, like I said, it is a slow build and you will need to get up to level 69 (I think) to unlock Barriss shards in the Cantina.