Potatohead, make sure you locate all of your wall studs and electrical before going the W route. Especially the center channel requires 16" on center or larger to fit. The results are fantastic but you do need to preplan. You can see a few pics of my setup here. I need to update these pics, but this should help give you an idea of what the finished product looks like. (Ignore all the during construction pics)

Dan
On-Wall M5HP LCR, QS8 & EP500 in 7.1