Magical Journeys can definitely help make the trip as painless in the planning stages as can be.

I don't know that any of the resorts specialize in this kind of situation (except Give Kids The World, but I think that's only for children with life-threatening illnesses), but all of them are well suited to special needs. Make sure they know about the Guest Assistant Card. Guest Relations will make sure they get the card that will fit their needs. I would suggest one of the values for the Disney fan - like All Star Movies or Art of Animation. Those will have the most "Disney" feel to them.

I hope they have a great time!