check the
vendor feedback forum for information about vendors in the U.S.
to purchase orchids from outside the U.S., you'll need an import permit from
APHIS. the exporter will need to provide CITES and phytosanitary certificates. there are few people with experience dealing with foreign vendors, so you're not likely to see much feedback about them. If you have a bad experience with a foreign vendor, there's little you can do about it, since they are not subject to U.S. laws.