The Acoustic Dreams and the Symposium racks are built like tanks and look great. Also the Rix Rax racks are really nice and he does custom work, he will build you anything you want.
Acoustic dreams
http://www.acousticdreams.net/Isolation_racks.htm
Symposium Acoustics
http://www.symposiumusa.com/
Rix Rax
http://www.rixrax.com/
Acoustic dreams
http://www.acousticdreams.net/Isolation_racks.htm
Symposium Acoustics
http://www.symposiumusa.com/
Rix Rax
http://www.rixrax.com/