Hi,
I have dealt with B&H several times in the past....and they are very good....Just call ahead of your arrival to make sure thay have one in stock.....This is the only place that I know of in NYC that I would trust with such a purchase......If you are coming to visit a friend in the states....shop on line and have it delivered to his address so it will be waiting for you.....You can also try Dave at Microphone Supply.....He's a good guy...I purchased my MixPre from him....but he's is in New Jersey...(very close to NYC)...Good luck and enjoy your visit....
Peace,
jk