Why the need for isolation?
The components that need isolation, such as the drive system on your CD or DVD player has built in dampening for normal applications (unless the train rolls right by your house every 30 minutes, you are considered to have a normal application).
Turntables are often needing additional isolation.
Unless you have an unusual situation, most off the shelf rack systems, such as those from Sanus, Plateau etc, will do very well.