Voltage for Full Stack NEMA 23 stepper?

Hi There.

So in the hunting and gathering process for my future CNC router /
mill I stalked and killed three NEMA 23 stepper motors. They are
spec'd out as Pacific Scientific Powermax II motors - 8-lead. I am
planning on running them bipolar (for nice, and mean projects) in
series. They are rated at 1.75A but none of the literature specs a
VOLTAGE at which to run them. On the label, it says "Vs(dc): 65V".
Normally, I would take this to mean that this motor is designed for
65VDC.

Is this the case with a stepper motor of this type?

Most of the controller boards I've seen only have capability for up to
35V. Any recommendations?

Thanks in advance for your help.

Bob