I read on this Forum that there is a place in Koca Calis that is doing Weddings I think it's on the beach..I am sure some member will know. However, The Golden Moon and the Mutlu will arrange this for you too. There have been members on here posting images of Weddings at both venues.
Also, the Kings Garden (although not in Calis) could do it to. Just email them and ask Salih..