The dresses under consideration all look very lovely. My main consideration would be how comfortable the dress in question is to wear for many hours to all day wear. Sequins are ok or if you’re too self conscious about them earlier in the afternoon, you could have some wrap that wouldn’t snag on the sequins (but that will be warmer for an already warm time of year and day.
The simple Dillards dress can easily be dressed up with jewelry & accessories that you like and can reuse.