You got a photo of your bot so far,

Also you can run the motor on 18v fine, it just won't have as much power

And lets get this bot done first before getting a cnc, I don't think your mother would happy with you getting a CNC router as they can have a larger footprint and costs £500 min to get one big enough for cutting featherweight and that is a "cheap" chinese router. Anyway some on near by might be able to help you out when it come to that.