Fast frequency generation/ modulation

Hi there

I am not really familiar with FPGA families and their spped grades etc

Is anyone here able to telll me what is the fastest clock signal and PWM signal I could output from a Altera FPGA or CPLD??

I am working on a project that I need to e generate a signal with a frequency that can vary from 0.1MHz to 50MHz and vary the duty cycle from 10% to 90%. Is there a device you could reccomend?

thanks