My family and I will be in Paris in late March and are planning a day trip to Reims. We'd like to take a tour of one or two of the champagne cellars - but with limited time and two young children (7 and 9) in tow, we cannot take in them all. Any suggestions as to which tours are the best? Maison de Pommery? Mumm? Piper-Heidsieck? Ruinart? Taittinger? Veuve Clicquot-Ponsardin?