We recently got back from our whirlwind tour of Peru and Chile on a very aggressive itinerary (blame goes to my husband :P). We also stayed at the Tambo and had a pick up in Cuzco and a full day tour of the Sacred Valley. I can highly recommend Sabino of DUP Tours (Destinos Urubamba Peru - duptours.com). One of the concerns we had was punctuality (given our limited time) and he was always on time (on the dot), very responsible and went above and beyond the call of duty many times during our visit.

I recently started writing a multi-city trip report (Lima, Cusco, Sacred Valley, Machu Picchu, Puno, Easter Island and Santiago) and he figures prominently in our Cusco/Sacred Valley posts (there's even a picture :P). My husband and I were thankful we made good choices regarding transportation/tours, most of which were due to the helpful advice of the good folks here on flyertalk.

Hope this helps and good luck with your trip planning! Here's the link to the start of our tour with him in Cusco - http://www.travelwhimsy.com/peru-and...ploring-cusco/