Finding the perfect Irish wedding song is no easy task. You might be better suited to looking for Irish song lyrics in general rather than for a specific webpage. That's because there are only a limited number of Celtic wedding artists out there. Rather, many Celtic musicians are happy to play, but only a few specialize in the service.
My group, the Brobdingnagian Bards, doesn't play too many Celtic weddings. However, we do have one of the most-popular Celtic wedding CDs around. There, you can find a number of Irish wedding songs listed there.
But again, look for romantic love songs. The Irish tradition has a vast number of those songs. But those can be found in many directories of “Irish song lyrics”.
Here are some romantic Celtic/Irish songs:
I'll have to look around and find some more in the future.