Azureus is a good choice, Bittornado's available and then there's the built in Bittorrent client.
It will work, but if you want both Linux and Windows to be able to acces the drives, have to use the inferior FAT32 fs, or stick with EXT3, but then you'll need third party Windows softwore that can read EXT3. I'm not sure what that is - but it exists.