Firstly, nobody calls it Canton anymore - Guangzhou is the Chinese name.
Where is BBK? Do you mean Bangkok? If so then your best bet might be to fly on Cathay Pacific from JFK and then you can travel to Guangzhou by train or ferry. You can either get a simple JFK-BKK ticket which would allow a stopover in HKG on the return leg, or get a CX AllAsia Pass (
http://www.cathay-usa.com/offers/aap/subdefault.asp ) which enables you to hop around all the places in Asia that CX flies.