I know you said you want to hand-write your notes, but unless you NEED to for some specific reasons, or are a terrible typist, I would re-think it. Most people can type considerably faster than they can hand-write, even under the best circumstances with pen and paper. Plus- typing can take advantage of modern spell-checking and auto-correcting functions.
If you MUST hand-write- I recommend a good smart pen instead, like those offered by Livescribe. It provides a good level of handwriting analysis and can make your notes searchable via an online app. None of the handwriting apps I've used on Windows-based tablets have come anything close.
If you are looking for a good, light, portable means of taking notes- I would recommend a good Bluetooth keyboard with an iPad. Many are very lightweight and small, yet have a good typing feel and are quiet (less intrusive in meetings or classes). Some are integrated with ipad cases, while others come with their own that fold out into stands. I personally love the Logitech Tablet Keyboard for iPad.
For software- I've gone between Evernote and Google Docs for my notes (I'm an IT executive and spend much of my time in meetings), and prefer Evernote because it doesn't require an Internet connection (if you pay for it), and I had too many problems with Google Docs suddenly becoming unresponsive in the middle of a meeting. I mostly went with these options because I wanted my notes available anywhere/everywhere. If I'm stopped in the hall and need to reference something, and I don't have my iPad with me- I can pull up my notes on my phone. Both Evernote and Google Docs are multi-platform and synced (almost) live.
If you don't want to pay for Evernote offline- a lot of people in my office use the notepad shipped as part of iOS. It does work very well for what it is.
