Maybe if you share with us your budget for the project that way you will attract more coders for the project. There are 2 ways to get a quotation for this, the first one is for the full project and the second one is to pay to the coders by hour.

I have experience in the casino's backend, and isn't much different than an exchange, the difference comes in the server. since a exchange is holding lot of nodes it needs a robust server.