I would forget the Omni-mount. I like your idea, and suspect that a slightly backed-out sheetrock anchor would be a bit wobbly for 10 lbs.. First, locate the studs and see if their locations are decoratively ok for the speakers. Then, take one speaker to the hardware store and find out what head-type (could be a flathead, panhead, or roundhead) and length of wood screw you need to reach 1 1/2 inches into the stud, thru the sheetrock, and still protrude far enuf into the room to fully engage the keyhole on the speaker back. Then do your pilot hole and set the screw so it protrudes *just* enuf (it'll take several iterations) to wedge the speaker against the wall, with almost no play, once the speaker is fully down on the screwhead..