It seems to me as if Jacob de Haan is not entirely unknown to John Williams... 
They both have a flair for grandeur and telling stories through music.
If you liked Ross Roy, try "Poème Montagnard" by Jan Van der Roost (
part 1/2 /
part 2/2) or "Pilatus: Mountain of Dragons" by Steven Reineke (
link)
The Wind Band (or Concert Band) repertoire is shock full of great composers and songs. And a lot of those are contemporary. I find it a nice change of pace from full on symphonic orchestras.
As for wind instruments in rock, I'm kind of partial to brass (trumpets, trombone). I usually love any song that features a nice trombone solo, or even just as rythmic punches.
