I have a 14ft conveyor I plan on using for my log trough. this should allow for processing a 28ft log, as long as the big end of the tree is placed forward on the conveyor. Not sure how well crooked, knotty, and twisted logs will feed, With a wide enough conveyor, might work. Even though you dont have a lot of support equipment on site, You must have something that will load a 40ft long log, or you wouldnt be attempting a deck to load on. With that in mind, I think your easiest, and maybe cheapest way of extending the deck would be a belt conveyor that could be set on and off at the end of your current deck. Make it with legs so it can straddle your trailer tongue. add a live deck and connect it to the current hyd's with quick connects. One thing I am thinking is will it be worth the effort. If the processor is going to stay on one site, than setup time wouldnt be a problems, but if you plan of moving the processor to different sites, then you would have to consider the time it would take to haul the processor and extra conveyor, hook it all together and then factor in just how long it would have taken you to buck the trees to length. Extra trips to a work site, setting up and taking down in preparation for transport, might take more time than just firing up a chainsaw and bucking a few trees to a length that fits.