who would use it primarily for note-taking?
Yeah, right! You say that now, but wait til you get one ... ;o)
Steer clear of the c700. I have one, and its fine for testing new versions of ROMs or whatever, but its fairly limited and slow. I only bought it because the guy selling it was including a 4GB microdrive, and at the time he was asking less for the bundle than I could have bought the card for on its own (I had the advantage of a good exchange rate).
I also have a c760 which I use daily and is great, which I haven't felt the urge to upgrade to the c1000 or c3000 yet, and think is the minimum you should aim for if you can manage it financially. There's no real difference between the c760 and the c860. For a discussion of the c860 and c1000 see this thread:
https://www.oesf.org/forums/index.php?showtopic=12300&hl=Mike.