Extra Payload

Hello can anybody help me out please.

We have a new 2012 Dethleffs Esprit i750 motorhome and we have found the payload to be very low once we have put all our bits in, we have weighed all our belongings that we need for a holiday with no item that we could do without and with a full tank of water we are over the mass weight by 50kg this may not seem a lot but we would also like to add onto our van a tow bar and an awning, can somebody please give me some advice or suggest a company that could help us out with increasing the payload.

we do wish to keep the cold water tank full when traveling  and yes i do know i could reduce the weight by 100kg if the tank was empty, but the weight of the tow bar and awning still take this over the weight limit.

Peter & Margaret