I would definitely just stick with your own choice. I always stand by my first choice, most of the time....Eva is good with stats and the skill set is good. She has a good atk skill early for her not be useless. But if you're really gonna be patient, I recommend waiting for Eva's RB, or atleast get her to 180 so she won't be useless.

If you want an alternative for the time being, I highly recommend shasha. She has an easy quest, and whats more, She has freeze which seals 2 enemies for 2 turns even if they are attacked unlike cord spell, Shizune.... It also gives a 10% damage bonus from all damage sources. So ya...shasha...