I'm in a similar situation, and am purchasing a Bryston 7B to run the one sub I have now, and possibly a better unit or two in the near future. My research agrees with the advice above. I had considered buying the 4B and running two subs from the stereo channels with the option to bridge, but a Bryston tech told me that in his opinion the 7B would be better because of it's ability to handle low impedances and deliver high current.
