isolation for built in stereo cabinets i'm plannin

hI folks: I'm having a carpenter friend build me some built-ins for a house I just bought. I was wondering if there was any material that I could place between the bottom of the stereo cabinet and the floor, one that will give solid contact but eliminate any floor based vibrations. I look forward to your replies.

The isoblocks that Mapleshade sells can be bought in large sheets. My HVAC technician puts it under A/C units to limit vibrations.
If you are building it in, have you considered Isolation for each component? That would provide more freedom to experiment for each components' need.
SYMPOSIUM much better Mapleshade is just ok.Get SYMPOSIUM Svelte shelfs and Roller Block JR HDSE.