In the end, it is dependent upon your travel itinerary as you can stop by the jungle ahead of or just after your tours in Cusco. From Lima to Iquitos you'll have a lot more flights readily available and probably also much less expensive ones than from Cusco to Iquitos. https://griffinfjoqt.sharebyblog.com/26642673/new-step-by-step-map-for-peru-amazon-rainforest-tours