You could try an AC servo motor. Like this:
Fanuc A06B 0163 B175 AC Servo Motor 1 8KW | eBay
You can't run these with a VFD - you'd have to get a servomotor drive and a power supply for the drive. It could get really complicated, but it could be an interesting way to go. I use a Yaskawa AC servo motor with an AMC brushless drive and a DC power supply to power a hand held spindle sander I made, and it works pretty well.