Settling for less than you need is a good recipe for wanting desperately to quit your new job way too soon. Salary is a touchy issue since most positions are budgeted, so only a certain amount of money is allowed for that job. But you shouldn't expect 'em to say yes. Vacation time's a little easier to negotiate since it doesn't change the actual amount paid to you. If the salary doesn't seem like quite enough, an extra week's vacation might sweeten the deal.
Most companies offer two weeks' paid vacation to a full-time, salaried employee.
They probably won't let you take all three weeks in a row, but that still means you can take a week off every four months. That's not bad at all. Maybe it's not exactly summer vacation, but you'll be the envy of a lot of your working friends.