There are a variety of HWH leveling systems available, the weight may vary according to the weight of your chassis and the size of the system you install.
Since the RV has already been made, I'd wait until you use the RV and decide if the expense of the system is something you want to pay for and get installed.
If you haven't 'pulled the trigger' yet on the RV, you might see if it would be cheaper to have it installed at time of assembly of the unit.
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI