Hi Syd, There are 2 main areas for beads in NYC. The jewelry
district is on 47th Street between 5th Ave and 6th Ave (a few places
like 46 Jewelry Supply and Metalliferrous are a block over on 46th
Street). Here you will find mostly precious metal and gem suppliers,
including many gemstone bead suppliers.
For seed beads you are probably looking for the garment district -
mainly on 36th Street between 5th and 6th Ave and the streets in that
general area. The stores there sell all kinds of bric a brac
including plenty of beads. Sorry I cannot think of a specific place
that would have the seed beads.