Thinking of Buying - Have a Few Question

I am a long time PC user who is about to buy a Mac. I need to install Windows onto a Boot Camp partition so that I can run a few specific programs.

One thing I really liked in the video was the seemless integration of User folders. It seemed like all files were kept consistent between the two. However, I currently have my Windows machine set up like this:

- Partition 1: OS Vista
- Partition 2: Data (In Vista the My Documents is pointed to a My Documents folder on this partition).

The reason I do this is in case I need to do a reinstall. It makes it super quick and easy to re-install, etc. Can I setup my new MBP so that it has three partitions and how can I use Parallels to provide seemless integration.

- Partition 1: OS X
- Partition 2: OS Vista
- Partition 3: Data (Point both the My Documents and OS X user folder to this shared space).

Can this be done?

Thanks!