You could probably pick up a 3-phase motor from somewhere that would do the job. My Myford is pretty flexible when it comes to motor mounting but it would be worth checking yours as they might have changed the motor mounting plate. Although seems a bit unlikely - Myford? Change?

If you download the manual for the Mitsubishi inverter that Tesla seem to provide, it does say that it can use an external 0-10V input for speed control so it should work fine in a CNC setup with a suitable breakout board or similar. After that, it's down to how much you want to put the control box together yourself with emergency stop, fwd/rev switches, speed control pot, etc. Price doesn't seem too bad for a reasonably put-together "bolt on, plug in, go" setup but I'm sure you could do it for less sourcing parts individually.