What's your budget? The Minus K (or similar) is probably the best isolation device to prevent footfalls from affecting play. The cheaper options are hit and miss as a lot depends on the your rack, listening area etc. More info at minusk.com
Turntable Isolation
Im looking for an isolation base for my VPI Signature 21. My listening room is over my garage and a times my footfalls cause the table to skip. What have you used that works?