Are you definitely looking for a lifemate for Sapient? My Toxshae (the Tenth) might work with her-he's a madman who believes he's a king, but he has a good heart underneath. He has no human form, though, and he can't breed at all. He'll probably bring his (adopted) son, Shawn, along (accidentally, of course!) as well.
Sapient just sounds really fun to RP with in general.