I completely agree. The fact that Sky was bonded to another budgie indicate that she's not the solitary kind. Unless such budgie has someone to spend most of their waking time with, they can't be happy. Getting Sky a friend is the way to go.
Try and find a reputable breeder in your area if you can, and see who's got babies available.
A good breeder will also be able to inform you on parents' temperament, which is a good indication of the babies personality (you want a bird who will be as compatible with Sky as possible).
Keep us posted!