Hamada

I want to begin with the fact I know little to nothing about wiring or electronics for cars. I've wanted to buy a new headunit for my 2008 tC for quite sometime now and I bought a Kenwood DNX6190HD off of eBay that was previously used for a civic si in fact he left it so everything is wired and setup for a civic.

I want to know what do I have to buy for the head unit. The seller said I would need a harness and other things. I think he said the cage is already installed (I don't know what that is) do I need another cage for mt tC? Please list everything I would need and if possible links to where I can purchase them.

Also would I be able to keep the controls on my steering wheel and the Ipod cable in the middle storage compartment?

Thank you for the help.