We were on a packaged tour that took the train down from Cusco to Macchu Picchu, so I can't help you with a guide service recommendation. However, once you get to Macchu Picchu, take the time to scramble up to the top of
Huyna Picchu. It's the spire at the far end of the site in the postcard picture view of Macchu Picchu. Definitely worth the effort for the view of Macchu Picchu from the top and a nice scramble with a couple of "interesting" moves along the way.