We celebrated a 60th birthday on our trip this past February. When I was making dining reservations I asked the birthday girl where she would want to eat and she said the 'Ohana for breakfast. It was morning EMH at Magic Kingdom so I made the ressie for 10am which gave us plenty of time to make Small World her first birthday ride (it's her favorite) before we headed out to the Poly. Some relatives who live in Orlando also surprised her by being included in our reservation.
I know it's not super Disney magic special, but it was special enough for her! Maybe just finding out his favorite place to be, ride or show or thing to do and letting them do it will be special enough? If they like more attention, go to MK and ride one of the vehicles up to the Castle. See if the driver will honk the horn and let you shout "IT'S HIS BIRTHDAY!!" while you head up the street?