I agree that
Aviva does sound light and fresh and I also get a nice zippy energy from it.
Ava, Viv, and Vee are the nicknames that occur to me. I think
Aviva fits in very nicely feel-wise with
Xanthe and
Sylvie but, since you ask, I do prefer the set of
Xanthe,
Sylvie and
Elodie sound-wise. I quite like
Eirlys but, for me,
Elodie and
Aviva both feel much nicer with
Xanthe and
Sylvie.