thnx very much thats all very helpful, its looking like for now due to the amount of money i have etc ill get the Sabertooth Dual 10A Motor Controller for RC which is £40

But im not 100% sure about something because ive not been doing this kind of thing very long,
but the motors are too fast and need slowing down, can I adjust the settings on the speed controller, or does it work on the more i would push the stick forward the more voltage is supplied to the motors- thus making them go faster?