This sounds like an awesome trip! Riding through the Peruvian Andes and making your way to Machu Picchu by motorcycle will leave a life-long impression. Ride safe, and post lots of pictures.
As to your equipment, I used a Camelback and was very glad I did. Unlike Costa Rica, the tap water in much of Peru can make you very sick. You can fill your Camelback with bottled water, or sanirize tap (or stream) water with a Steripen UV light to ensure a supply of safe drinking water.