Actually, I kind of dislike my recommendation, because it's still a consumer-grade laptop. I see it as the best of the worst kind of thing. :(
If you can order from Lenovo directly, I'd go with a business-class ThinkPad, personally. Your budget is pretty tight, but the ThinkPad Edge, while not as nice as the T-series I recommended to Adelynn, is still most likely going to be better than most consumer laptops in terms of build quality, durability and reliability. And I was able to configure a decent one for a pretty affordable price of $589.
[Image: http://img199.imageshack.us/img199/6128/capturevby.jpg]
Used their CAPSCHOOLSALE coupon.
How high is the budget? If they're willing to spend more money, you could upgrade the CPU to an even faster model, or whatever. I picked the middle E420 (14") base build and customized it to what I posted there.
If you're interested, you can mess around with the Edge builds here:
http://shop.lenovo.com/SEUILibrary/controller/e/webca/LenovoPortal/en_CA/catalog.workflow:category.details?current-catalog-id=12F0696583E04D86B9B79B0FEC01C087¤t-category-id=C3B63C6B34338DEC6E6C9796B5EF912F
Or go for 15" if you prefer, although I didn't check the pricing on those.