Would anyone know of a place where I can buy sheets of Ostia? It's a very thin unleavened "wafer". If you've ever eaten real torrone it is the stuff on the top and bottom. I like making torrone at home (much less expensive) and use buttered parchment. It's good but not 100% "authentic". Maybe a bakery supply store someplace?
If you've never had a good torrone (the cremona style, not the sicilian kind) you might try Isgro bakery. At $15 a pound it's a bit pricey though.