The original Dark Horse Angel and Buffy comics (i.e. the ones set during the TV shows, not the ones that take place afterwards) are being released in digital form.
continued from Buffy #29
However, Buffy the Vampire Slayer: Classic #29 is "Haunted", not any part of "Past Lives".
I'm guessing that the numbering of the Buffy Classic doesn't match the original numbering (which is what the Angel reference is to).
Which (digital) issue of Buffy does contain the middle part of the "Past Lives" storyline?