Some info on the stepper drives: (mainly marketing stuff, still looking for product tech info) but the print on the unit is probably enough to work off

Looking at this, the drives are set up for half current 2000 steps per rev.
1)High performance, low price, low noise, excellent stability
2)Features16Stall angle constant torque subdivision
3)Uses a unique control circuit, effectively reducing the noise, increased rotational stability
4)Maximum response frequency of up to200Kpps
5)Stepping pulse stopped more than100msWhen the coil current is automatically reduced by half, reducing the number of occasions the motor overheating
6)Bipolar constant current chopping mode, so that the same motor can output more speed and power
7)Optically isolated input/Export
8)Drive current from2.0A/Relative to6.0A/Phase separation8Speed adjustable
9)Single power supply voltage range:AC18-60V
10)Error protection: thermal protection; over-current, low voltage protection
11)Compact:YKC2608MIt is an economical, compact stepper drives, volume151 * 107 * 48mm2 Net weight0.5KG
Overview:
YKC2608MIt is a constant angle and constant torque stepper drive high-performance segments, the driving voltage AC18-60V, a single power supply. Adapter current 6.0A or less, diameter 57-86mm of various types of two-phase hybrid stepping motor.
YKC2608M-HIs a constant angle and constant torque stepper drive high-performance segments, Driving voltage AC18-80VA single power supply. Adapter current 6.0A or less, diameter 57-86mm of various types of two-phase hybrid stepping motor. With a cooling fan!
The internal drive bipolar constant current chopping mode, the motor noise reduction, click on the run more smoothly; increase the drive power supply voltage so that the high-speed performance and greatly improved motor drive capability; when and stepping pulse stops over 100ms, press Select Lock is set for the semi-flow / full flow. Pulse frequency is not only used in times of high low high segments, improve the accuracy of the stepper motor operation, reduced vibration, noise reduction.