The Jen'saraii were the light-side equivalent of the Hej'sorai, they were another ancient group. They were around before the Jedi (in my Universe).
They were able to become immortal (somehow), and were primarily teachers and pacifists rather than fighters although they would fight if you gave them a good reason to. The Jen'saraii weren't like the Jedi, and didn't have non-conformists because they were lax and allowed people to basically do whatever. They didn't really see themselves as Peacekeepers or enforcers. They also had rivals in the form of the Light Templars.