For cables of different lengths and ratings, we normally recommend vendors such as Molex or Binder. Binder is an example of a vendor that also offers an M12 connector for even greater flexibility (example for X-coding as used by the Gigabit Ethernet interfaces of the IW3700: Search Binder Products | Binder-USA; the connector is the first item on the page). We are also planning to qualify and release an M12 to female RJ-45 converter option, but for the majority of the applications we see, M12 is preferred due to its greater vibration resistance, better corrosion protection, and IP67 protection.