I have never seen a fairy wrasse or a flasher wrasse that was aggressive to another fish. One thing to consider about fairy wrasses, is the colorful ones will be super males, fairy wrasses are harem fish, and if not surrounded by females the males will change sex to female and may be drab looking.
That said, I am partial to the Hawaiian flame wrasse, the Scotts fairy wrasse and the mystery wrasse. If I were you, I would pick the one I liked the best. Make sure to quarantine the wrasse as they are very skittish and should become acclimated to captivity by themselves, when picked on by tank mates, they will be very susceptible to parasites and disease.