I think having Maggie being Barnabas' desire to be Josette worked on many, many more levels (we're talking about the original series here) than if he would've first picked Victoria. First, Maggie looked like Josette; Vicki didn't. "Psychologically," that works perfectly. Whereas Vicki had all the infatuation regarding Josette, and even fantasized about being her, Maggie had no interest, care, concern or knowledge about her, other than maybe one of the old legends. That would make her a much harder nut for Barnabas to crack. He came out of the coffin after 175 years angry and bitter and that would make him a shallow, self-absorbed man. He didn't care, at least at first, about all the nuances of what he wanted to do. He saw his Josette physically, and that's all he wanted to use. He loved Maggie's image as Josette, and yet he had no feelings for Maggie the girl - it seemed he actually had a pretty good loathing of her when he abducted her. He wanted to erase her personality, kill what made her Maggie (take away her identity - what would an angry, shallow, elitist "man" like Barnabas care about some person named Maggie?), and that struggle as presented in those tension-filled months was portrayed brilliantly. So here you have, to Barnabas, a beautiful young woman who was his physically perception of Josette, yet had none of the personality of his lost love. Magnificent!
To be honest, if it had been Vicki, Snoozeville. With her obsession and infatuation, one bite, one playing of the music box, and that would've been all that was needed. And she didn't even look like Josette. Where would be the challenge in that? Might as well just have had Barnabas snatch Mrs. Johnson. That way, he could've had his Josette and ironed shirts, too.
Gerard