Hi, I was just wondering which Macbook Air you guys can recommend, and from what site? I have no problem getting a Refurbished model . I will use it for: Web Browsing, youtube, research, and writing papers. I want something that will last me a few years also. Something that is fast, and won't be slow with my tasks. 13 inch or above screen . Thank you! If possible, under 850.00 also.