I would call to your attention the article by Allison Beavan, National R & S Chair for Senior High Music. It appears in the Aug. 2006 issue. Her ideas for selecting high quality literature include using repertoire lists published by states (New York, Georgia, Texas), ACDA repertoire lists, and conducting books that contain repertoire lists. In addition, I would add the lists we have published here in Iowa, i.e. the new teacher's guide, and our own web site (click on the various Repertoire and Standards sites). I have also been reviewing one octavo each month selected from the new music I receive from publishers. These reviews are archived and found on the senior high link. There is no shortage of high quality choral literature out there. You just have to look in the right places.