Sota Eclipse packages for VPI tables.

The Walker is ridiculously expensive for what it is.

The Eclipse package, which includes a better than VPI motor will perform even better than the Eagle with the VPI motor.  You can begin with just the motor and control.  But for the full effect you will want to add the RoadRunner which not only reassures you about platter speed, but will control the motor to keep the speed absolutely stable.

Lewm is quite correct. Forget the Walker. I would not buy a shoe lace from them. Get the full package. The Road Runner will make sure the platter continues to spin at the selected speed regardless of whatever drag is placed on the motor. Mass will save you from abrupt speed changes but not slow ones. The Road Runner looks at each single revolution and not a small segment of a revolution and adjusts the speed gently making sure each revolution occurs within the exact time selected.
It is a much different approach than most negative feedback systems use, looking at a larger interval. It is difficult to hear slow changes relative to fast changes which are more obvious. As an example let's say you use a sweep arm during play. When you put the sweep arm down on the record you subject it to more drag and over a few seconds slow the platter down. The road runner detects this and slowly adds more torque until the speed gets back up to 331/3 rpm and holds it there. The correction is so gentle you can't hear it and you can rest assured knowing that regardless of what you do the platter will spin at exactly 331/3 rpm.
I think this should make a great improvement on your turntable. The next thing you might want to consider is an isolation platform you can put it on.
The best is the MinusK but it is expensive. There are others on the market. I think Townsend makes one that is less expensive. You could make your own with a little cleverness. Even better you can attach a dust cover to it. 

The next thing you might want to consider is an isolation platform you can put it on.

My turntable has an air bladder suspension.  The stock VPI suspension required you to fill each bladder separately, but since I was already running my ET 2.5 off of an air compressor with a precision low pressure regulator, I removed the valves from the air bladders and ran tubing from each of the towers to another precision low pressure regulator.  It made a huge difference vs the stock setup.  I can literally tune  the resonant frequency of the suspension while the table is running.  I can hit the shelf (1.5" thick maple) with a mallet with no sonic issues whatsoever.

@vinylzone. I must ditto @lewn’s advice.  I have the Sota predecessors Eagle and Roadrunner driving a heavily model VPI HW-19 MK IV.  It is a great improvement but you get nowhere near the full benefit without the Roadrunner.

@vinylzone. I must ditto @lewn’s advice.  I have the Sota predecessors Eagle and Roadrunner driving a heavily model VPI HW-19 MK IV.  It is a great improvement but you get nowhere near the full benefit without the Roadrunner.