I heard with a dump trailer frame that twin cylinder is the worst since if not evenly loaded one side may go up a tad faster and twist the body.I have an N&N dump trailer. 6x12 - 10k GVW for registration purposes. They make a 7x14 14k version though.
Fully galvanized with front mounted 3 stage telescopic cylinder. Made in Montreal and sold throughout Canada and the northern US. I love it - no issues at all.
I've used dump trailers in the past with single stage dual cylinders and they could not dump heavy loads (stone/gravel) because cylinders are aligned horizontally during first part of lift. When the most amount of force is needed, the cylinders are at the greatest mechanical disadvantage.
I personally won't buy another PJ trailer. I had a 2012 that I bought in 2017. It was so rusty by the end of '18 I could hardly sell it. Powder coat was coming off in sheets the size of washcloths. Painted trailers from now on for me. Ymmv.Thank you for your reply! Looking at pj brand dumps.