How do I go about bi-amping Martin Logan Ascents

I am way new to this topic, and have no idea what I need, but would like to try this experiment. I am curently running the Logans with a Threshold 300 Stasis II. I also own a Mac? I believe 150 power amp I would like to work in the system. I am also using now MIT 4 9.9 Enhanced Image Bi-wire. If the experiment didn't cost me much I would like to throw the Mac. in I hear this could make a real positive difference.
*Do I need a external x-over?
*Do I need new ICs?
*Do I need new Speaker Cable?
*Is this whole thing just dumb?
I'm new here be gentle. Take a look at my system in "Ever Evolving"