I would try any of the following, all located in NYC but they would
most likely ship to you:
-Wongs Jade Corp. (212) 354-9554 (ask for Mr. Wong)
-Stone International (212) 686-2090 (ask for Irene)
-Taj Company (212) 944-6330 (ask for Salim)
These are all reputable dealers with fair prices. Make sure to tell
them you're "in the trade". Good Luck!