Oh, congratulations
morm!
I agree with the others that you should keep pursuing Rian. I don't see why your wife wouldn't go for it...it's a quite pretty name. Hmm...actually I know someone named Rian. She was (briefly) one of our Residence Life Advisors while I was studying abroad in the Netherlands. I wonder if her parents were influence by Tolkien.
But if not Rian, the I think Arien would be perfectly fine as well...I've always been fond of that name.