The only real closed loop stepper options are KMotion or LinuxCNC.
Almost nobody runs steppers with a closed loop controller. It's just not necessary.
The IP-S only works with Mach3, Mach4, and CS Labs new SIM CNC.
Mach3 is obsolete, and I've heard that CS Labs Mach4 support is poor.
You might want to look at Centroid's Acorn controller.
You need to work on that design, as imo it needs some work.
1) The gantry sides are too small, and too tall. The gantry beam will sway side to side a LOT.
2) Ditch the bottom bearings on the gantry sides. The only reason they'd be remotely helpful, is to help stabilize the too tall sides. Otherwise, they double the cost, with little benefit.