Never heard the
survey company, but doesn't mean that they are not good.
For any work on the
boat, I am sure there will be all kind of people to do the job in Istanbul. Nonetheless, Istanbul will always be much more expensive than Marmaris in terms of marina,
haul out (if you need any) and workmanship.
If the boat can safely sail, Bodrum and Marmaris are better options. If you choose to come here in Marmaris, I can help you with the marina berth and works.
Cheers
Yeloya