CAN to PWM converter?

[asid61]

After reading the recent thread on motor controller selection, I realized that if a poor-ish team wanted to use CAN they would have to drop $40 more than a SPARK to buy a Talon SRX. Does anybody know how one could have a separate PCB that would act as a CAN device and relay commands to a Spark or Victor SP as PWM? I anybody could help me with it/answer case-by-case questions (like how CAN commands would be set up, how to set up a particular chip) I would be very grateful.