Both, but if you can only get one it's hard not to recommend the standard, which is still Office. If you need to have Office but would prefer to write in something else, remember that basic .txt and rich text editors are very capable. Anything from TextEdit to the various third-party solutions are, in my opinion, superior to Office. Also, .txt is probably the most accepted format in the computing world, and will almost certainly exist and be readable in the future (which is a big deal for me). iWork is fine, but it hasn't been updated in a long time. We know that there is another version, thanks to leaks from around the time the MAS launched. However, Apple held it back at the last minute.
It definitely is iPwn. MS Office is the standard for office documents and things right now. iWork may work, but MS Office is the standard. It's what's used. And for stuff like this, it's better to conform before you get teachers, professors, bosses, etc saying, I can't open your @#$%ing document! EDIT: I don't know if you know yet, but MS Office does have a University version that includes Word, Excel, PowerPoint, and Outlook for 100 bucks. You may want to look into that. IDK how it checks if you're a student or not though.