haven't seen the video but good on you for finding it.

In terms of battery packs from component shop, a 12v pack or two 6v packs in series will give you a 12v battery pack which will happily run your motors. I wouldn't recommend over volting for your first machine as you want to keep it as simple as possible.

This pack here should do what you need it to http://www.componentshop.co.uk/12v-3...tery-pack.html