Looking for Expert C++ coder that has experience Implementing GPS devices Communication Protocols

Hello there, we have a GPS Platform that deals at the moment with several devices at the backend. The backend of the solution is built upon Windows services coded in C++. The person whom develop these services is not longer with us and we are looking for a person or a company that can step up for that person and help us to develop the respective windows service each time we want to integrate a new device into our system (The services at this moment are built in C++, but we will prefer that in the future , future services are built with C#, but that is something we will discuss with the person we make an agreement with) This will be a permanent position and an ongoing project. so dont look at the price on the project because fees need to be negotiated with the chosen party.