There are just as many, if not more hybrid hissers being kept overseas, it's easier to find pure stock of many species here in the US than it is in the EU for example... There's really only one pure Gromphadorhina species/strain that's being bred with any regularity in the EU that we don't have, (however the purity of said cultures is being called into question, it's possible oblongonota got mixed in somewhere along the line), and one Princisia color morph which may no longer exist as pure stock either.
You're better off looking for reputable dealers here in the US claiming to have pure stock, that can verify their purity with recent pictures of their colonies, lineage tracing, etc...