Causing Extreme suffering sounds pretty F'd up, and they are slaves so killing them will basically end their slavery and allow them to become one with the Force... I guess.
Seriously though, it sounds to me like your problem was that you chose Sith. All of there choices are bound to be skewed since they are uh, EVIL, and all.
I did a republic Smuggler quest where I was supposed to get this medicine back from a thief that stole it from the military. I had to find the thief first though, so I go out looking and it turns out it's some really nice Cathar chick who just wants to help the kids. She wants me to return the medicine to her so she can keep the kids healthy because as it turns out it was stolen from her by some separatists.
So I go and I kill like a whole colony of people to get this medicine. After said slaughter I return to town where my two choices are A. Give it to the kids who might be sick sometime in the future (Light Side) or B. Give it to the soldiers from whom it was originally stolen who are sick right now (Dark Side).
I don't know, but that one seems a little more like what you are looking for maybe. Try rolling Republic.