I think that most people would pronouce it Aay-uh. I don't think the connection to ire is too great - not a problem for me. Though I know where you are coming from - I ruled out Noah as I didn't like that the name starts with No (as opposite to yes)

I like the idea of using a "virtue" name and continuing the "theme" from Grace. Faith is nice, but I also like Prudence, Charity, Constance, Patience, Trinity. I don't think you could use Honour though!