does any one know were i can buy sprockets that match the the two sets provided in the kit of parts 
ifi robotics sells #35 which comes in the kit and andy mark sells #35 and #25 sprockets.
do you know were on the ifi robotics site it is because i still cant find the 21 tooth output sprocket.
The tips and good practices has a list of suppliers and IDG also supplied sprockets. http://www.idglink.com
I like these guys, http://www.martinsprocket.com/, They have gears and those things too.