Mark, I live in an 1870s townhouse, with plaster walls. Using a masonry drill bit and correspondingly sized plastic anchors, I attached by QS8s to the walls using the t-anchors. I also mounted my center speaker VP100 over the plasma using the FMB in the same manner.
I don't play music at ear bleeding levels, but I've had no problems (fingers-crossed) with either surrounds or center speaker working loose.
This solution is not nearly so elegant as what you are describing for your place, but it does work for me. Just thought you might want to consider. Cheers!
