that is a software issue, i think after version 4.3 you get the a2dp (stereo bluetooth support).
I own a 8100 with software version 4.5.0.102, and i use a samsung stereo bluetooth headset and it works great.
I think you just need to upgrade the software.
Take a look at this thread for software upgrade and more:
http://www.blackberryforums.com/gene...ee-memory.html