Ok .. so you want to play
The only reason I asked is because I designed and built my own that is now capable of over 40K RPM. It is not using any fast micros (a Mega 8 running 8 MHz) and an external chip that handles the PWM (being clocked at 25MHz). The speed will be way too slow to handle doing any Fourier or other DSP type algos between PWM updates. It is not needed anyway. I run highish PWM frequencies that will not help your situation as well.
Nobody here is doing anything that I am aware of, with more powerful controllers. It all about cost and small size it seems.