I just recently joined this forum, and realizing this is indeed an old thread, I still want to give it a shot.
I'm located in downtown Los Angeles, and I'd be interested in buying this much quantity. I don't know where the goods are located, but I can suggest the following:
fly to Los Angeles, assay it, have a certificate, right in front of you, and based on that I can pay for the goods at the bank (cashier check, wire, etc).
If I am successful in buying, I can even pay reimburse you part of the airfare.