What a wonderful tribute to your parents. I absolutely love the magical possibilities for celebrating special occasions at WDW.
I would recommend any of the following:
Visit
Disney’s Fairy Tale Weddings for information on Vow Renewals.
Call the Concierge at your hotel for ideas such as cakes, flowers, etc. You can also inquire with the
Disney Florist.
Dine at
Victoria and Albert’s at the Grand Floridian after enjoying spa treatments.
Dine at Cinderella’s Royal Table for dinner. Pre-order the Cinderella Slipper dessert by calling 407-824-7091. They can even write Happy Anniversary on the plate in chocolate. (I had the white slipper at our Vow Renewal and the chocolate slipper at Cinderella's Royal Table. They are spectacular!)
Enjoy a Wishes Fireworks or Illuminations cruise. Add food/beverages to your
specialty cruise aboard a pontoon boat.
Best wishes to your parents on their 40th Anniversary!