With that much labor involved, I think I would probably try and talk them into going with the Wiremold Access 5000 raceway instead. It's an 8-inch low profile nonmetallic baseboard system that can handle both line and low voltage. You can get it in white and a few other colors as well as a couple of different wood veneers to match the existing interior.
The best thing is that you can make the inevitable future changes like additional outlets, phone and CATV jacks without having to break out the rotary hammer and chisel. Wiremold Access 5000