First time travelers to Europe, planning a 3 weeks holiday- 4 adults and 2 kids (9&5) flying into Paris in Jan 2016. Planning to spend time in Paris, Switzerland (Zurich, Lucerne and Zermatt), Austria (Vienna & Salzburg), Prague and couple of days visiting relatives in Duisburg, Germany before heading back to Paris for return flight to Australia. Any advice on most appropriate routing and mode of transportation (air/train) to get to destinations above would be very much appreciated. Thank you muchly