The first one is definitely Forward to Time Past.
The second one sounds like
Her Way by: dreamweaver - After Spike burns up in the Hellmouth, Buffy demands that the Oracles send her back in time.
Or, it could be
Prologue to Life/I Know You by: Slaymesoftly - A response to a challenge at the Bloodshedverse where Buffy is returned to her season II body with all her post Season VII memories. She is there due to a spell Willow performs to try to help Buffy get over mourning for Spike.
Both of them deal with a Post-Chosen Buffy being returned to the Season 2 timeline circa "School Hard". Hope one of these is what you were looking for.