I have the BOSE 321 series 1 system. Here's a photo: It comes with two speakers that do a solid job, but I'd really like a home theater system with rear speakers to get the full effect. Does anyone know or is familiar with BOSE and it's system? I looked in the back of the system, and it's hard to tell if I am able to buy a few extra speakers and hook it up, or if this particular model is just not upgradeable. Also, just in case, what not too expensive home theater system would you recommend buying (if this doesn't work out?) THANKS.