[@Natsucooldude] Just pick the one who has the best porn made of them. Or pick a name out of a hat. 

Or, hell, the Plain Doll is pretty much the Hunter's canon waifu. You could say her.

EDIT: Oh shit that reminds me, [@Wernher], is Izzy still part of the Lightning Slayers, technically, or has she left and become her own faction?