Marc, I'm quite certain those sites are all on the European side. To get to the Asian side you need to cross the Bosphorus. Geez, hope I'm giving you correct information. It is such a fabulous city. I'd recommend staying in the Sultanahmet area of the city. It is so close to the major sites and convenient to jump on and off the city tram.
We didn't board the ship in Istanbul but did a 4 night trip prior to flying to Athens and boarding the Voyager.
