想买笔记本, 请教如何具体挑选或请推荐, 多谢!

Basically, for a budget about $1k, I'm thinking to use the notebook for my school study, some office work (documents, spreadsheet), and a little multi-media processing.
Also I want it to have fast internet surfing, lightweight construction, good portability, relatively long battery life,and potential for future upgrade.

Thanks a lot in advance!