I've used these guys before.
They seem to be able to handle large orders, and they have some good info, too.
You might want to consider diversifying some of that cash, though, and not put it all into gold.
In an attempt to address the causes and effects of the Great Depression, Executive Order 6102 was signed on April 5, 1933 by U.S. President Franklin D. Roosevelt. It prohibited the "hoarding" of privately held gold coins and bullion in the United States. The Order was given under the auspices of the Trading with the Enemy Act of 1917, as recently amended. The government required holders of significant quantities of gold to sell their gold at the prevailing price of $20.67 per ounce.
The limitation on gold ownership in the U.S. was repealed after President Gerald Ford signed a bill legalizing private ownership of gold coins, bars and certificates by an act of Congress codified in Pub.L. 93-373 [1] [2] which went into effect December 31, 1974. P.L. 93-373 does not repeal the Gold Clause Resolution of 1933, which makes unlawful any contracts which specify payment in a fixed amount of money or a fixed amount of gold. That is, contracts are unenforceable if they use gold monetarily rather than as a commodity of trade.
, and it makes one want to sell everything, but it always comes back
(hopefully!)