Rodeo Roundup is fun. Space 220 is nice, but IMHO, once you are out of the elevator, it's slightly anti-climactic. Maybe consider Hoop Dee Doo Revue - the show and food are really good and they will acknowledge his birthday during the show. We typically book a wagon ride after the show as well - could be a special birthday night. We also really enjoy Topolino's breakfast if he would like a character meal.