For the panels we use PVC board or Sintra board (brand name). Sign shops are able to print directly on this by a process called DTS (direct to substrait). The sizes you will need are 33.375″ x 21″ for the individual panels, 70.125″ x 21″ for the full back 2 piece love seat panel, and (if you really want to get nuts) 105.625″ x 21″ for the full back of a three piece sofa. Every major city will have multiple shops that are able to do this. We have used multiple shops and we were able to get prices to average $41.65 per 33.375″ x 21″ panel (printing and PVC included).