I had problems with my sidewall placements, as well (fireplace on one side and french doors on the other) and ended up using small bookshelves (Axiom M3's) and some adjustable wall brackets (Axiom's FMB). The left surround ended up being a bit creative, as I mounted to the side of the cabinet instead of the back as originally intended. You can see the left surround here and the right surround here (on the left side of the picture).