Actually, I've taught a wedding couple using this song, and we alternated between American (square) Rumba and East Coast Swing. The music changes back and forth between very slow, mellow sections, and faster, more upbeat sections, (even though the tempo remains the same.) If you have the time to learn two dances, this combination fits the song very well. And both dances will be very useful to you at parties and dances and such in the future.
Also, I would highly recommend that before your wedding, you take at least one private lesson with an instructor who is willing to take a look at what you know, and help you to be as comfortable and confident as possible. You don't want stress over your wedding dance to take away from your wedding day, and you don't want to discover when you look at your wedding photos that you should've stood up straight or kept your eyes up!
One more tip: Think about your dress, and what size back steps you are able to take in it. If it's very long or very tight and straight, your step size will be very limited. This is another issue an experienced instructor can help you to figure out.
Hope this helps!
-Melissa