Nappanee Windows make a ramp gate that is spring loaded so it can be lifted closed quite easily by hand:
www.nappaneewindow.com
One of these that will hold 2500 lbs + is going in my RV-Garage rig to get up to a full sized car into the garage. We are putting a winch in there to pull anything in slowly. The cost for the ramp gate is about $1100.
This is being built on a KW T2000 and the living quarters are rather minimal, 14 ft behind the drivers seat and then an 18 fr garage behind that. The garage drops down to a lower level behind the drive axles and we have a removeable ramps to get motorcycles, gokarts or a car's front axle on the upper level. No sloping beaver tail. We've put this on a 301 inch wheelbase and let the thing get out to 42 ft. total length. Hope to have it completed in a month or so.