Sith work better under a Zader lead than they receive credit for. I would sub in Boba for Nihilus, his ability block is more effective IMO than DN's cooldowns increase, and his execute move is essential for Chaze/GK. It's also a lot faster for a first-kill than using DN. You might also want to sub in Zavage for Zylo if you have him, keep the taunt up on SiT and synergize with those "ignore protection" attacks.
I currently run a team of Zaul, SA, Zavage, Zylo, and EP. Sometimes I'll sub in Zader leader against Chaze teams, and every so often I'll forget to switch back to Zaul at the end of the night, and the Zader lead actually tends to fall less overnight.
Hope this helps!