Rhumba is a good choice. For one thing, many other dances place you so that the two dancers never actually look at each other; in rhumba, you can and should look at each other with passion and intensity- which sounds right to me for a wedding dance.
Lots of other good reasons why it would be easy to learn and to look good on the floor. Have fun learning and remember that FUN is the goal when you start thinking about who is making mistakes.
Jerry