An interesting project. To have a great TT you need great speed - easier said than done. You also need great vibration control - also easier said than done. No wonder the high end is so expensive. There are may vibrations. Most of them are like germs - you do not see or feel them but they are there. To make a list: 1. Ambient vibrations in the room 2. Footfall. 3. Sound waves from the speakers. 4. Stylus colliding with the vinyl. 5. Friction of the bearing on the thrustpad. They are all deadly because they get magnified some 10,000 times by the time they come out of your speakers. Your solution will address 1. & 2. My advice is to not forget the other causes of vibration.
I myself do a little bit of this and little bit of that: Aftermarket feet ;(Isonoes); a PEEK (species of teflon) thrustpad; Mass (granite slab); Platter Damping (epoxy under the platter, quality mat, dynamat on unseen parts of the chassis). Finally those vibrations that cannot be reduced or damped are 'tuned' in an attempt to sound benign. So I use ebony - they make oboes and clarinets from the stuff. Ebony stabilizer, ebony armboard, and ebony headshell.
I myself do a little bit of this and little bit of that: Aftermarket feet ;(Isonoes); a PEEK (species of teflon) thrustpad; Mass (granite slab); Platter Damping (epoxy under the platter, quality mat, dynamat on unseen parts of the chassis). Finally those vibrations that cannot be reduced or damped are 'tuned' in an attempt to sound benign. So I use ebony - they make oboes and clarinets from the stuff. Ebony stabilizer, ebony armboard, and ebony headshell.