I don't think there's a European reseller of the Richeson brushes (sadly). The da Vinci series 5073 synthetic mottler is a very good alternative. It is slightly stiffer but the bristles are just as soft and make a lovely smooth finish. They are also _much_ more rust resistant than the Richeson brush. These are widely available in the UK and I assume across Europe because they are German.
Here's the da Vinci website: http://www.davinci-defet.com/englisc...and-80-mm.html