Mac Computer Remote Access

Hi We would like to a way for our remote Mac developer to access our Apple machine remotely and work. We have 1 option of teamviewer but that is not feasible as it is very slow and developer is unable to work. We are having many developers working through windows RDP on other projects and would like to have such a option for mac as well. I know VNC is another option but windows to apple vnc works sometimes and does not work at other times. We have several such tasks so want an expert who can do it fast. We have very small budget for this and cheapest qualified bid will win the project. We also want to make sure ftp both ways are blocked- whether user tries to ftp our mac machine or user tries ftp any remote machine from our mac machine. Ideally we don’t give our source codes to freelancers so that is why we want to achieve this.