Don't use Bitstamp. They are currently not performing USD fiat withdrawals. My guess is some kind of money crunch or theft that they refuse to publicize. There are people that have been waiting over 2 months for their funds to be moved out of Bitstamp. There are people looking to spearhead a class action lawsuit against them.
USD withdrawal is problem on all exchanges but not that serious, some manage to clear this problem. Me personally go for euro cuz im from Europe and its instant payment to my card.