Taig offers two controllers for their mills. The basic one is an open-loop half-stepping system that's generally reliable with Mach3. The more deluxe DSLS (Digital Servo Lock System) counts steps as they're executed, and compares them to the readings from encoders on the motors. If they get more than a certain number of encoder counts off; an error is triggered and the machine shuts down. This can save a complex part, if you've got a lot of time into it and just clipped a clamp by mistake. A license for Mach3 is supplied with every CNC mill. You can also run them with other CNC control programs, but Taig will have a harder time supporting and troubleshooting if your system is unfamiliar to them,
You can also order any of these mills CNC-ready, which means they come with NEMA 23 motor mounts but no stepper motors, control cables, software, or CNC controller. If you want to build your own motion control solution, this would be the way to go. But I don't think that 26v system you mentioned is going to be powerful enough to run that mill to its full potential You'll want something with 50 volts,or more for steppers with even moderately low induction. And no, if you choose the 5000 series mills with the ball screw option, you don't need to worry about backlash compensation.
I have a website at https://computersculpture.com/machines that explains more about the various options available with the Taig/Microproto mills; we also offer a discount on Taig's products.