Unfortunately, many of the new systems don't allow for much outboard processing. The 901s require the use of their proprietary active eq.
The upside is that all you really need is a 2-channel amp to go between the Bose eq. and the 901s. As you've probably already read, many people do this to their HT setups anyway. A more powerful amp should really help push the 901s.
Receiver L/R preout -- Bose active eq. -- Amp -- 901
I guess you already knew that. So, all you really need to do is add the other surround speakers for HT.