My Bose 901s were an entree into "high-end" audiophilia 25 years ago. They were supposed to simulate the reflected sound you'd hear in a concert hall. I have, on occasion actually turned them around (with the 8 speakers facing forward) for a more focused sound. Now, my critical listening is through five Mackie 824s and an lfm-1.
Re: Using the 901s for surround. I think you might have some difficulty wiring the things since the dedicated equalizer must be used with 'em. It would be interesting to hear how things go with your proposal.
Jay