Analog Stereo to Run Spin Class

I would like to use my analog stereo (Alon Phalanx speakers, Blue Circle BCG 3000 pre-amp, and Llano 400 amplifier) to run a spin class.

To run the class I need a CD player with volume control that will control the pre-amp volume. Can this be done to run a pre-amp and 400 watt amplifier? Recommendations?

Second, I need a loudspeaker to be used by the instructor tied to the spin instructors headset. Can this be wired in through the CD player? Do I need a separate system?

Your ideas for this and advice is appreciated.
Why do you need a CD player to control the volume when you have a preamp? I would introduce a decent quality line (and maybe with phono also for future options?) mixer with a mike jack between the CD player and the amp and not use your preamp.