Depends on what do you need, what kind of lineup you're using.

Oh yeah, and the bracket that you're in. If you're confident that you will move first most of the time, then I think susanoo kakashi is a good choice. Your lineup also runs really well with susanoo kakashi. But, if you face a lot of edo hiruzen or agk, or if you want to play safe, then it's edo itachi for you.

In short, susanoo kakashi makes you more destructive, but edo itachi makes you more stable. It's just my opinion, in the end it's up to you.