Balancing would be different for every party, depending on number of players and their skill.
I can't upload my NPC's as they are very campaign specific. (and locked within a saved game instead of a "prepared GM campaign") I doubt you"ll have a use for Cronossi Soldats, Shaiguhrah Rangers or Eastwood Bandits.
This table I made may be of some help:
points per level Personally I don't think NPCs do have to be fair though. I just think up a type of NPC or Monster and asign skills that I think they should have because I think it would be cool, or logical for them to have those.
Creating and balancing encounters is one the most important skills for a GM and the only way to master that skill is learning by trial and error.
I do think that the standard NPCs and Monsters provided by Larian do a decent job as templates though and I doubt that a NPC Generator would do a better job at providing what you need.
As a GM you simply can't escape designing, or tweaking, your NPCs and Monsters and equiping them with the gear, items and skills you think they should have.