Sith Team Help

I'm working on a Sith team and need some advice. I have Darth Maul (Zeta lead, gear 10), Savage (Zeta, gear 10), Palpatine (gear 11) and Vader (gear 11).
I need some advice on my 5th member. I've been using Dooku for now, but i feel like there's probably a better option out there. What have you used/seen that could make this team better??