Theres a tank on ebay, bigger then you need but maybe a bargain, in your areahttp://cgi.ebay.co.uk/250l-window-cleaners-water-tank-/320675580178?pt=UK_HomeGarden_CLV_Cleaning_CA&hash=item4aa9c10912
I have a 24ft power pole if you are interested plus gutter-hook, brushes etc