Replacing Anilam 5000M - Recomendations?

I have a few stepper motor CNC routers running LCNC and just got my hands on a Republic-Lagun VBM-1000 with a wonky Anilam 5000M controller that may need replacing if I'm unable to cost effectively fix it. As this is my first foray into servos, I'm looking for advice. The mill is driven by brushed DC servos. The electrical cabinet is all Anilam, including the servo amplifiers. I'm driving the steppers on my CNC routers with Mesa 7i96's and would like to stay with Mesa, unless you all have other ideas. Please lay them on me!

Thanks, JT, especially for turning me onto the GS2, which I guess is now the GS20 series. Do you leave the manual spindle speed control set at high speed/maximum rpm? I'm guessing the analog or frequency output from the VFD can be wired to the Mesa board to display spindle speed on LCNC?