Try contacting Muse at firstname.lastname@example.org. They are very helpful and will tell you if the 100's are capable of being wired in mono.
If they will not configure as monos, you might consider using them in a vertical bi-amp situation.
Hmm. I think Muse 100 models were the ones I use to have.. Its been over 10 years and cannot remember to be quite honest however they were MONO only versions that I owned. I do believe I remember there being a stereo version as well.. You might not be able to Bridge them, however you can probably conver them to the standard mono block. Also as mentioned you can Vertical bi-amp them as they sit right now no problem, and could be even more effective or desirable depending on the speaker, this is simply taking a bi-wireable speaker and running one 2 channel amp with the left channel feeding the highs, and the Right channel feeding the lows for example, but you will need a Y- spliter RCA set to send the same signal (mono) to the 2 channels to be the same on one amp if that makes any sense.