[Biased turkey]

I have the Scalextric rally starter set and would like to purchase an aftermarket controller.
I run the cars with no magnets
The set comes with the Scalextric sport power base.
I would like a controller that produces low maximum speed

I have 3 controllers in mind:

Parma 217N7 Controller, 60 ohm, for Scalextric Sport and Ninco

Professor Motor PMTR2113 Scalextric Sport / Ninco home set controller

Professor Motor PMTR2119 Sport Semipro controller for Ninco & Scalextric Sport
It says :suitable for low voltage and no magnet cars.
If I purchase that one, is there an easy way to reduce the voltage of the Scalextric sport power base ?

Any suggestion is welcome

Jacques