Another option... if you have an alarm supply store in your area they usually carry a wide range of mounting brackets used for security cameras. Many are very simular to omni brackets and a few you can get extensions for. The good thing is they can be had for much less than what you pay for speaker mounts in a stereo shop. You can go to a hardware store and get a 1/4-20 thread insert/heliacoil (don't hold me to that spelling) and it will fit 90% of those brackets. Good luck in whatever you choose.
