New to AVR - want to do PWM with atmega2560 for LED sign

[tdg8934]

I have a MikroElektronika BigAVR and MikroBasic comming to design an LED sign (SPI based) with PWM support. I have never used AVRs before but used Parallax Basic Stamp 2 and SX28 / 48 chips for a few years now with LED design projects. I am thinking we need better PWM control than what is available for the Parallax micro-controllers. Is this the right way to go with AVRs especially the 2560 - or do I need to use FPGAs for something complex like this? - If so, where do I begin?

Thanks.