I'm currently working on an Old Republic campaign for my group with several of my old pbp characters as central villains. The problem I am having is trying to figure out how to make sith NPCs to be used. Obviously they are different then some of the dark side user npcs I have found. But I am just hitting a wall on the best way to make a balanced sith npc. I'm just looking for an example of one. I know from there I would have a better direction, so if anyone has one to show I would greatly appreciate it.

Just use player character exp amounts to determine certain strength levels. A Sith Acolyte would have base exp, a stronger one might be 'knight level' and a master might have 400-500 starting exp.

I posted about this in another topic, so I won't go into super detail abitbit, but...

I made a nemesis level Sith Apprentice to be an antagonist for the party. She was Warrior: Aggresor with all of the fear and terrify talents. She also had the foresee and influence power. She dual-wielded red lightsabers and had really powerful superior quality gear. Her primary go was to try and use all the fear mechanics to attempt to turn the party to the dark side, while her regular combat skills were just high enough to not be steam rolled over.

If you're not looking for anything that complicated (like minion and rival NPC's). Then I would suggest using some basic melee brute from the book, replace their melee skill with Lightsaber, and add 1 or 2 force powers they use dark side pips for. With just 1 or 2 force rating max. Or just give them a base talent that emulates dark side force powers without having to worry about force rating.