Jack,
Not sure what you need the extra foot or two for coming off the deck. I see many step decks with a device that supports the load at the same height as the upper deck. I don't know what they are called, but I will try to describe one.
Picture a box beam. Let's say 2 pieces of steel or aluminium tube 6 inches square and 102" long. One tube is on top and the other is the bottom. They are joined at the ends by 2 more pieces of tubing giving you a rectangle as wide as your trailer and as tall as the distance between the main deck and the upper deck. The interior of the "rectangle" is made up of more tubing, some cut at 45 degree angles to support the weight. The ends fit into the stake pockets.
These allow you to bridge frieght that is longer than 10' coming off your deck. I have seen step secks use 2 or 3 of these spread out on the lower deck to support a long load.
If you just need 1 extra foot off the upper deck, 2 of these tucked up tight would do it. And if you won't be moving them around then steel would be the way to go. Alot cheaper but heavier.
Some that I have seen I'm sure were home made. But I would think that somewhere someone is making these and selling them. Check on-line places that specialize in flatbed and heavy haul equipment. Sorry I don't know what to call them other than "deck extender box beam load bridging thingys.
Hope this reply was perfectly clear. If not I will do my best to confuse you more. Just ask.
