Residency and work permit (Istanbul)

We are about to move to Istanbul and intend to work as independent consultants (mostly for clients outside Turkey). We had intended to set up a business under sole proprietorship and pay taxes to the Turkish Government. We were informed by the Turksish embassy in Nairobi though that without a work contract in Turkey we would not get a work permit. We also hear that the procedures have become really difficult and long and you may be rejected without any justification. We were informed by other friends that without a workpermit we would not be able to import our household goods.

We are now wondering whether we should apply for residency permit only and register our business in Germany (if the Turkish Government does not want our taxes we might as well pay them to the German Government). Would a residency be sufficient for customs clearance? Could we be in trouble with Ministry of Labour?

Do you know an affordable and reliable agent in Istanbul who could advise us and assist with application and customs procedures?

Thanks

Anja