Your husband sounds like a wonderful man, but he's pretty lucky to have you as well for trying to make this trip so special for him! I hope we can find some pixie dust to sprinkle!
The Walt Disney World florist at
www.disneyflorist.com is one of my favorite places to get in touch with when I need to make a visit to Walt Disney World a little more special. They have everything from fruit and flowers to plush characters and whole celebration packages. There is something for every budget, but if they sky is the limit, I love Mickey Mouse's Grand Welcome package. You can see the package
HERE . One nice thing included in this package is a personalized blanket, and that might be something nice that your husband can take with him to the hospital when he has his transplant surgery to help him stay focused on happy times.
You could check for a dinner reservation at the Rose and Crown at EPCOT. If you time it properly and are lucky enough to get a table outside, you'll have one of the best seats in the house for Illuminations, the night time show at EPCOT.
Make sure to stop and have the Disney photographers take pictures of your family together. You will get a Photo Pass card from the first photographer, and from then on, you can just hand that card to each one of the Disney photographers. When you get home, you can check online to see all of the photos of all of you together. That's so much nicer than pictures of only part of the family!
Best wishes to your husband. My dad had a kidney transplant and did really well following surgery. I will wish the same for your dear husband!