Try http://www.gimsonrobotics.comwww.gimsonrobotics.com and look at there kits there cheap and they have ready to use motors with gearboxes and u can get wheels that fit straight onto them from gimson too. or just buy some 10 quid drills from argos and u have the motor and gearbox and batterys and chargers but dont know how well the batterys would work with the bot.