I am not qualified to talk about this stuff, but what I will say is that Monoprice inwall speaker wire in bulk is super cheap. Like, even as 12 AWG, 250 ft is only $60. I say throw it all up there, just in case. Smarter people would tell you to run conduit in the walls, so that you won't have to tear anything down. I mean, remember component cables? They are going to be outlawed by HDMI/HDCP regs? Will they have 5 years from now, some new and improved HDMI 2.6 cable that can handle 2x 1080/60 streams for 3D? What is KB wire? I vote for doing as much as you can right now.