I need advice on bi amping

Are you two done now or do I have to send you to your rooms? ; )
All insight- even though contradictory at times- is an opportunity to learn, so I thank you all. 

I bought the additional amp and will try things out. My thinking is I bi wire each side with a horizontal configuration as the amps are not actually going to be exactly the same even though they are the same model. And here I go into the vortex.

A challenge I see is that the old Citation is set up for two "system" outputs, so one to each amp, but I also need my subs connected. One is a Phase Tech 10, the other an Infinity, both powered. 

With amps that old, careful about channel to channel and amp to amp matching.  If you have an AC volt-meter and a test CD, you can measure it fairly accurately, just keep the frequency at 400Hz and lower on your test signal.  Run the test CD, and measure the output voltage at the amplifier on all channels. Even with speakers connected, at the amp, the voltage should be really close on all channels. A 12% voltage difference is a 1db volume difference if my math skills have not failed me today.

So I received my 2nd Quatre DLH 100 and wired it into the system to run the high pass with my other one run out to a subwoofer and then back to the low pass on my Veritas 2.4s. Everything is sounding great and looks good, too.