From my experience working with other directors who were percussionists... If you want to be a head band director some day, don't accept a job where you don't have a concert band to direct. Maybe it's the 2nd SNV band, it's still a band. And you can move up from that band.

Also, don't dismiss the small school route, way more less likely to get pigeon holed in the "drum guy" category, and get a good chance to do some great work as well with full bands.