Here's my version:
Faith still loses her watcher to Kakistos, and goes on the run. Not having a Buffy to run to, she stays on the move, going from place to place, trying to avoid her enemies and herself. The only reoccurring face she sees is a mysterious guy named Angel who always seems to know where she's going, and wants to help. Faith turns him down. Faith doesn't need help.
After she finally faces off Kakistos and wins, the Watcher's Council finally catches up with her. Faith quickly realizes the Council is bad news, and they join the list of things she is running from.
I want Buffy to be called, so Faith would somehow have to die and come back. Maybe she bonds with some human OC who saves her the way Xander saved Buffy. However it happens, Buffy gets called. Faith ends up meeting and helping to train the new slayer, but there is a lot of tension. Buffy just wants to return to her normal life - the kind of life Faith didn't even have before she was called. But the girls bond, too. They are in the same boat now.
That's all I have.