I'm going to run my Sony ES cdx c90 to the Sony xt-40v tuner because of the HU t.v controlls. Now, the question is since I'm going to use "non" sony screens do I need optional equipment. I'm going to install 2 monitors for the headrest and a monitor in front. I heard of an optional RC-70 accesory. How and why would I use this. I also need to know what other accesories would I need for a very flexable setup.