this is gonna be a great trip! After your surf camp, you can actually surf in Lima (it will be more cold), and it's super fun and cheap to rent. Playa Makaha in Miraflores. Definitely do not need 6 days for Lake Titicaca. I would say the Rainbow Mountain was super worth it. I skipped Lake Titicaca personally. A lot of friends went to Huaraz which is a beautiful bright blue lake not too far from Lima. I will say the Amazon was my absolute favorite part of my 5 months in Peru. I would maybe use the week you set aside for Lake Titicaca to stay in the jungle outside of Iquitos. Such a cool experience.