The Archives and Special Collections unit at Santa Clara University has a Nilfisk GM80. It's pricey and has some features better suited to museum/rare collections (v. low suction, for example).

If you're looking for a (much) more economical vacuum for bound periodicals, say, that are rare/fragile. Our perservationist recommends the dual speed DataVac Pro. She's not sure if it has a HEPA filter, but the specs do indicate it has a triple filtration system. She used it at Towson to vacuum main stacks periodicals and books. It's a bit loud, but it works.

Happy shopping!