Fantastic, thank you both! I'll get one of those bought then I don't know what's good for 4 drive motors at once, my only other bot ran using servos and microswitches and two motors, so this is all new!

The ESCs were called '320A speed controller for car/boat/buggy' as well but I really can't find anything other than that... the description wasn't too helpful either! I think it might be a peak - sounds a little bit too good to be true, seeing some of the amp ratings on some of the ESCs out there, but they do only go up to 14.4v. They were the same model as these if that helps - http://www.ebay.co.uk/itm/High-Volta...item20cffabd44