For fast and easy sail design download the latest version of SailcutCad. It is a FREE sail design program that is pretty darn good. You are on your own with reinforcement patch size and placement but that is no big deal when all of the hard stuff is done for you. The program allows you to print the panels on big paper.... I would take the DXF files to an architect and have him print out the panels on large paper... it turned out to be very cheap going that route. I ended up designing the sails but had someone else sew them together... my sewing machine didn't like the dacron I was working with.