You can raise the limit to $10K per day ($50K per month) by upgrading the account to "verified" status.
You can further raise the limit to $100K per day ($500K per month) but upgrading to "trusted" status.
https://support.mtgox.com/entries/20919111-AML-Account-StatusesVerified isn't to tough but it does involve sending KYC/AML related information and my understanding is Mtgox has a backlog right now. Trusted is a total pain in the ass in the US as you need not only a notarized document but also to have the notary validated by getting an apostle seal. This involves a three step process: 1) get documents notarized, 2) send notarized docs to state to be apostled, 3) receive apostled documents back and send to Mtgox. It took me about 2 weeks (and that was without a backlog) from start to finish.
Bitstamp had no upper limit that I am aware of but you must be verified to withdraw or deposit more than $10,000 USD (or equivalent).
I would offer the services of my company but we do not have wire capability at this time and keeping funds in stock has been a challenge. Just curious, have you considered bullion? Depending on your needs we may be able to work out a custom sale of bullion.