I have an old 2011 13" MBP which works great (and will work even better with Mavericks) and will do all necessary. For lectures, I will be using notability on my iPad for note-taking and evernote for audio recording.
Here are some good apps:
iPad: PDF Expert or Goodreader for note taking on PDF's. Evernote for typing notes and recording audio and syncing to laptop. Pages for on the go work processing, numbers for on the go excel, iStudiez Pro for being on top of school work
Mac (I haven't used windows in the last 5 years or so): Evernote, iStudiez Pro, iWork or Office (I prefer iWork)