I would use Photoshop to prepare the photos and an audio editor e.g. Adobe Audition or Garageband to prepare the audio.
Then either Powerpoint (Windows) or Apple Keynote (Mac) to run the slideshow.
There is a feature in Lightroom that will make a movie of a set of photos set to a piece of music. It will automatically figure out how long to show each photo for based on the number of photos and the length of the song.