Don't know if this is what your looking for, but this is one of my favorite fics and it just popped into my mind so I thought I would mention it. Faith doesn't come into the situation until later, but she doesn't, 'go off the rails', and her and Buffy have some issues but they work them out. Spike is also human at first, but... well, things change.
A Different World by Ms. PerceptionKinda AU. At the end of the world, a vampire with a soul made a wish that those he loved would have a better life. This is story of that life and all the ups and downs in the lives of the new Scoobies.