If you want nice upscale paper goods; in the past I have bought beautiful design party goods at Venture and Gracious Home.
I would Call first to make sure they still carry paper plates and stuff.
212 288 7235
On Madison Ave and 86th Street
Third Avenue, at 70th Street; (212) 517-6300
Or their other store
Broadway @ 67th St.
A really nice upscale on-line resource for party goods.