Passively bi-amping with another CA-2200 will get you less than 3dB more output. Using the CA-M600 will get you almost 5dB and, probably, more head room.
I won't stir the hornets by commenting on bi-wiring but I use shotgun cables on my 800D2s, fwiw.
I won't stir the hornets by commenting on bi-wiring but I use shotgun cables on my 800D2s, fwiw.