Hi Sound - maybe I can help you. You want a rack that has a frame that is rigid and drains down to the spikes. Shelves can be of many (debatable) materials as long as the material has a LOW resonance frequency, which is why glass, metal, and granite by themselves are not suitable. You can sandwich or bond those materials to lower the basic resonant frequency, but essentially the shelf material should not "ring" when knuckle tapped. The shelves should be cone/spike connected to the frame, which will then make them as close to individual platforms as possible. You can then tightly couple the components OR further isolate the component from the shelves. Component isolation can accomplished with things like Rollerblocks, Stillpoints, Ceraballs, even inexpensive devices like Herbies Audio Iso Cups and balls. I hope this helps you with your quest.