I dont know about that headset being available in the package, but about N80 and N80IE,
IE stands for Intertnet Edition, and the only difference is that the firmware for IE is different, it allows you to download some applications through an Download Client, which is like a utility which includes links to some applications like Yahoo! Go etc. Also, it includes some utilities which allow for a better utilisation of the Internet, like direct uploading of Images to your Flick account etc.
If you do not use GPRS, then IE is not for you, and anyhow theres no other difference between them, so better you go to N80 only.