And I don't remember either, unfortunatly. Just that its all human, fairly long and I think Buffy starts out dating Riley and he turns abusive.
The all human fics are in a definite minority on that site at least.
Edit:
Found It!!!!!
Shiver by spikeslovebiteSummary: When her mother dies, Buffy inherits her art gallery. While poking around in the attic one day, she discovers a strange painting. Learning the identity of the man in the painting becomes her obsession.Now, we just have to see if its the one *you* were thinking of.