Moray, probably one of the most important design considerations in a full sheet plasma table is to have nothing projecting above the surface which the sheet lays on when the gantry is positioned at the end of the table for sheet loading. In other words, work toward building a TABLE to load the sheet onto, and not a BOX to try to stuff it into. This sometimes requires a bit more design creativity with respect to the frame and gantry, but that extra work is nothing compared to attempting to wrestle full sheets of material in between a pair of rails. Even a sheet of 16 ga, which weighs only 80 lb will feel like it weighs 300 when you find yourself in an awkward position in trying to place it on the machine. Over the long haul, the ergonomics of any machine will be the factor that makes you like to use it or hate to use it , much more so than how perfectly the machine itself may perform.