Yeah I wouldn't advise going from a tank to barrels , you will really physically feel it at the end of the day lugging barrels about, time consuming as you'll have to keep an eye out for the water finishing in each barrel , this could be when your at the back of a house and you only realise when the water stops and you've got to waste another 10 mins trying to get rid of the airlock . Like Duncan said, might be an idea to get a 7 seater van or similar