Which speed controller

I have a Wilson Benesch full circle turntable. Would like to know anyones thoughts on speed controllers and which one is best
If you are not already using a power conditioner, the PS Audio P500 does the job of a power regenerator and a speed controller. Assuming the Full Circle operates off a synchronous motor, you just plug it into one of the four regenerated ports and you can lock the speed within 1/16 RPM. 60 hz gets you 33 1/3 and 81hz gets you 45 . It also has a clean feature which works something like a degauzzer.