Our MS kids bought into this one: Fanfare for a Holiday Celebration by Robert W Smith. Not 100% sure if this is what you're looking for. I don't know the specifics of what your band might need. The trumpet part ranges from second line g to second space c. Clarinets have three spots where they are playing second space c, but it starts right on it after a rest and then goes to second space a. Low brass go up to Bb on the top space. There are a few spots where trombones and baritones have different parts, they are not unison the whole time. There are two measures of ww glitter at the beginning, If you have lazy flutes/clarinets they will show their true colors, but it is very playable. There is probably enough percussion for 6 players.

A Christmas Proclamation, also by Robert W. Smith, is also a good one, but again, I don't know exactly what you're looking for. The low brass have a feature near the end and we had them memorize it a couple years a go and stand and play during the Christmas concert.

Good Luck! Hope you find what you're looking for.