we are doing something very similar, our practice bot consists of 4 cims in a tank drive, and maybe some sensors and a minibot deployer. we have yet to test to see how fast the code runs, but i think it should work fairly well.
http://www.arduino.cc/en/Main/Software
is where the arduino software can be downloaded, it is a different programing language, lab-view may also be usable but i don't know for sure. a digital sidecar is not needed as the PWM wires plug directly into the arduinos digital IO pins. an arduino also has 10 analog ports, which can be arranged in any way necessary.