Exar Kun FS (legal upon release in November Destiny of the Force V-set), is a tremendous improvement to Naga specifically. Not only do you gain the -4 to SS saves, but you also get his poison saves up to a natural 20 - which together with Bandon (also from DotF V-set) makes Naga a reliable 50 (60 if you are haunting him and giving him rage) dmg hitter and spectacular with double SS rolls. All you need now is some reliable init control and Naga can become an absolute monster and one of the top game controllers in the game - and more importantly, powerful enough to negate Dodonna and high activations within the Sith.
As to your current squads, I'm not a fan of going with Naga and Freedom, as you aren't really making good use of Freedom's CE, or taking the full power of Sith Sorcery.
I would prefer a squad that uses init control to set up the SS saves (heck, this might even be a role for Darth Revan), but more likely make it into an MTB engine. I'd probably consider going with Exar Kun, Naga, and the MTB set up, or alternately, with Naga, Uliq and Mando support.
Here, I made some examples for you.
Exar and Naga
http://www.bloomilk.com/Squad/Details/93230Uliq and Naga
http://www.bloomilk.com/Squad/Details/93232