"March of the Robot Brigade" by Bernotas (kinda hokey but the kids will
"Plaza de Toros" Michael Story (watch out for them concert D-flats tho)
"Nottingham Castle" works with your clarinets/trumpets in mind. Lots of doubled parts, minimal divisi. But in F, so lots of A/E naturals
"Armory" by Standridge is repetitive enough, and one clarinet part.