Kibble

Does anyone have a recommendation for a private transfer from the Istanbul cruise terminal to the IST airport? Our cruise docks at 9 am and our flight home departs at 3 pm. We are looking for a couple hour sightseeing option so that we can be at the airport by noon. Also, when we arrive in Istanbul we are thinking of just taking a taxi from IST to our hotel in Sultanahmet versus prebooking a private transfer. Any thoughts on that as well would be appreciated!