Just an idea. I am currently using Solid Tech racks. They have two lines, Radius and Rack of Silence. With Radius, you can add springs under each and every shelf. With the Rack of Silence, you can also isolate even more with springs except the top and bottom shelf. See the following page for more information:
http://www.solid-tech.net/extreem.htm#2
I have the reference level Rack of Silence in my main system. It works well with everything in my system except the turntable. I have the Michell Orbe SE, a suspension table. So I placed a butcher block atop the top shelve and set the table on it. Seem to work well.
I have a totally tweaked-out Radius in my study room holding my headphone-based system. It has springs under each shelf and isolation feet under the rack.
Prior to the recent change, I was using Solidsteel racks.
Disclaimer: I am not affiliated with Solid-Tech. Just a happy customer.
FrankC