We recommend staying in the Rockwall area, which is about 15 minutes from the venue and about 45 minutes from DFW airport. There are a number of good restaurants in Rockwall as well as a nice lakefront area called, The Harbor.
If you want to explore downtown Dallas, we recommend the Dallas Museum of Art and the neighboring, Klyde Warren Park. The Perot Museum of Nature and Science is really neat and kid-friendly. If you want to pair a happy wedding with a somber excursion, the Sixth Floor Museum is a common attraction. You can also go there to watch tourists almost get run over while they attempt to get pictures at the spot where Kennedy was shot.