Suggestions for Bi-amping using 440-Pro CI

[audio_engr]

Presently, I have the 440-Pro CI that I use for bi-wiring my B&W 802 D3. Should I wish to Bi-amp my 802 D3s, using my present 440-Pro CI as a pair of monos, what additional Devialet units do I need to buy ?

a) Another 440-Pro CI 

          OR

b) 2 units of 220-Pro CI 

          OR

c) 2 units of 220-Pro CI companions 


There will be only 1 Remote (which is the existing one with my 440-Pro CI). 

Also, I use my 440-Pro CI with the RCA-to-AES digital Link. How will the 2 more units link to the present 440-Pro CI ?

Suggestions from you will be much appreciated ... Thank you !