the faster the pic runs the higher the minimum PWM frequency is, idealy I need a 125 Hz PWM output but can settle for 250, but that means running the pic at 4 MHz, my thought was if the pic takes 4 cycles / instruction and the AVR takes 1 then in a similar situation with the AVR I would have the same PWM frequency but effectively 4 time the code speed,
after looking into it a bit more I think that I may be able to pull it off with a pic which is the best was as I already have the pic's and the programmer and the knowledge needless to say I have already developed the program.