A colleague of my wife's is a middle school marching band and concert band director.
He wants to get into arranging with Sibelius, Finale or the like.
What about instrument sounds for the ensembles he'll be arranging for? I suppose the Garritan Jazz and Big Band library would cover most of the sounds needed for high school concert band, but what about marching band at high school football games or pep band for sitting in the gymnasium at basketball games? Ensemble marching snares and toms come to mind.
The Native Instruments Kontakt Gold library for Sibelius seems to address some of these instrumental needs.