We had around $16,000 in savings when we arrived.
We use Bank of America, and you can withdraw money from Barclays without any fees (they are the bank with the "special" relationship). We also have a Capital One Visa, which doesn't charge any fees either.
We decided to leave our money in our US savings account, and just using the Capital One to buy most things. We then pay it off with our savings. Since the exchange rate is so bad, I didn't find much point in moving ALL of our money over, so this way we are only moving over money as we need it.