my first impression of Zilla was the same as your wife. Then I started to visualize crocodile dundee saying zilla and it sounds ok.

I think the wife got the better of me and was doing some reaserch over the weekend and found Zilla is a girls name in hebrew. Just not sure now that i have that in the back of my mind!!
I think we've decided to wait till he joins us and see what name suits him then. With Zilla now on the backburn, we are both pretty happy with Duke or Cooper, but again we'll wait and see.
Man, and i thought picking names for our kids was hard!