I think you may have some confusion going on.Can you fill in a few details about your prior experience with CNC?

Briefly,you need an RS485 to communicate with the machine and it will be connected to a USB port on the computer.This is how you send the Gcode to the controller.Whether you use Vcarve or Fusion is your choice and either will cost you in one way or another.Commissioning and calibrating a router to perform all the functions that you need is not a small task and you are unlikely to improve on the functionality that the machine originally had.