Looking at the Huntsman website, you could buy the 1T eye-to-eye kit for ~$280, add the electric brake kit $215 and then you just need to add the handbrake & cable (say$40), for a total of $535. Mechanical adds another $35 from what I can see. Note that you will need to weld the backing plate to the axle, but that is very simple to do.
Most people buy a 1T trailer kit and register the trailer with a max weight of 750kg, so don't need brakes.
How close to 1T will your loaded weight be? I always like to have a bit of headroom to allow for possible overloading, bad track conditions, etc. The 1.4T setup might not be such a bad idea for the sake of the extra $50 or so.
