I am thing of putting it between the walls and putting a face plate on the wall. Has anyone done this before? How did the sound come out?

What would be the next step above AudioQuest Type 4+ wire? How much more would it be? Would it be a wast of money?

I am looking at Axiom M60v2 speakers to go with my Yahama 861 Receiver and Marantz CD Changer.