This is a picture of my tailgate buddies Sundance. He had a welder fabricate a removable carrier for his generator that weighs in at 250+ lbs. There are two long hitch receivers welded to the frame rails with the cantilever support rails extending about two feet underneath the trailer. Since this photo was taken he has painted it black and removed the railing on the door side so he can use a ramp to load the generator.
This carrier has hauled his 250 lb generator and gas cans for the past 2 years with ease. We did a fat boy test the first time we loaded the generator, with us standing on the platform too, it seemed to hold the 750 lbs without a problem, standing still. You are wise research if you can safely load a 1000 lbs on the rear of you trailer.