before ordering/fitting any kit like these check the calipers have dirt seals, the AP kit (available on there web site) It uses calipers that begin with a 3 no dirt seals. Only AP calipers that begin with a 5 have dirt seals. You will still req them in the USA as you will not want to be wanting to clean/overhaul them every few 000's miles.
You definatly dont want bigger discs on the rear otherwise the rear end will pass the front end and you will end up in a meat truck.