Looking for ideas on rear ramp door

[82Motorsports]

I have an enclosed trailer that currently has swing doors on rear. I want to build a ramp door to replace it as my ramp idea doesn't work real well. The trailer sits higher than some so I'm looking to lower it first, but I'm looking for help on rear door. Anyone done this or tell me what to look out for in the build? What type of hinge(s) work best? Cable and pulley system, etc?

Thanks,
Dave

[Buhr Racing]

Just a thought....I saw a trailer that had the barn doors on the rear but added an outside full width ramp to the back of it..It just folded up behind the doors and had a a latch system to keep it in the up right poistion when traveling. You could also do the same by welding single ramps to the back instead of full door. This way you dont have to do anything with the existing doors that are already in place.