Sharing same itunes library between bootcamp and OS lion

Hi, I recently changed from a PC to a mbp.
I am often using bootcamp with windows seven to run several applications.
I only have 500GB of HD space, so I like to keep most of my files on an external portable drive.I’m going to buy a 1TB portable hard drive, and transfer all my music files from my old PC onto that, and want to sync it to both my itunes on the bootcamp partition, and the OSX partition.
I’m going to buy a windows formatted one, and then install something like NTFS 3-G.

Firstly is it possible to sync the files on the portable hard drive to two different itunes? (bootcamp and Os lion)
I plan to manually create and add folders for the original music files within the portable drive, but when I add music to my itunes library, say while using bootcamp, will the itunes library automatically be updated in the OS itunes as well?Will this work, and what problems may I face?

Thank you!

 

has anyone tried this??