If you want to experience Istanbul stress free, and absorb all it’s historical significance, I recommend hiring a local tour guide.
Our guide Hanifi (professional and licensed), offers very flexible tours and can custom design a program for you based on your stay and interests. Private air conditioned car, reasonable rates, and in depth background and insight into the city, its people, and its history are what he offers.
Here’s his site for inquiries:
Enjoy!!