I have two Onix Rocket RS2250mkII speakers I need to mount on a wall. The will be the two rears in a 7.1 system. The problem is they don't have mounting hardware built in. On thought was to purchase omni mount 30 with a bottom mount and construct a platform that screws into the holes for the feet. Maybe even purchase two extra bottoms for the speaker and adapt then to fit the bracket and bolt them to the speakers. I don't want to drill into the speakers. They weigh 25lbs each. Any mounting suggestions?