Do a bit of score study. You can do that on Youtube these days - nearly every piece released in the past 20 years has a play-along score from the publishers there.

Find a piece or two that have multiple trumpet/clarinet parts. There's still a very few pieces that even have three. Adding those extra parts and textures "matures" up the sound quite a bit if your kids can play well and you have the numbers.

Early English Suite by Duncombe may work for you. Russian Sailor's Dance by Gliere/Williams isn't too basic sounding. Connemara Sketches by Osborne is a great piece and is underplayed. Your kids may have fun with Phantom Ship by Del Borgo. Three Renaissance Dances by Moss is playable too - and you could work up multiple movements and simply perform only 1 or 3.

Basically - I would recommend you take a look at UIL Regions that are historically inner-city/urban regions (5 for Fort Worth, 11-12 for San Antonio, 20 for Dallas, 22 for El Paso, 23 for Houston), even though some of those inner-city ISDs have moved to other regions this alignment. Lots of those high schools have entered as a NV and played a Grade 1 in the past 10 years or so.

Finally - remember that it is technically LEGAL for you to play the same music your middle school feeder played, if playing from the same category, even if it's educationally unsound and quite unethical. If you absolutely can't find a better piece ...