Thre best rack/stand I have used to date is from Lovan - cost around $400 for a 4 shelf unit
It's their entry level stand similar to this one...
http://www.lovanaudiogroup.com/sovereign-series.htmlBut buying the stand was only the begining...
- I added sorbothane between the shelf and the steel frame
- I made thicker shelf for the TT and amp to stand on
- I added 12" x 12" granite tiles under source components
- I added foam (drawer liner) between the granite and the shelf
- I added 18" x 14" 3/4" thick granite under the TT and amp
- I added Large isolation feet between the floor and the stand
Now everything is very stable and vibration free
You can fill the legs with shot or sand as desired, by in my case the granite provides the mass required to keep the stand stable
Each shelf has spiked feet which I believe helps keep each component isolated
I do not think i would use a wall mounted shelf on a timber-framed wall because te wall can vibrate. Trying to stop that would ba a huge task
Hope that helps - Steve