Can i add more software i2c to arduino Due

Hi ,

i need to connect nearly 32 x 200 (6400)slave i2c devices to arduino due.

I am using various i2c channel multiplexer in between ardunio due.

Now since there is bus capacitance limitation, i need controller with more i2c buses.

In arduino Due , it provides 2 hardware i2c bus. Now if i need to configure any io pins as i2c lines, then how to do.

I have seen some software i2c master can be added in arduino. Upto how many no of software i2c lines (sda/scl) can be added???. Is that adding only one possible so?

can anyone clear doubts. i welcome good ideas and suggestions

Thanks in Advance