Are you putting it under plexiglass or lexan?  If so, shop around for a good large format printing company, and take it to them in whatever format they like.  Photoshop is a good format, it lets you specify the dimensions of the print job within your saved file, to pretty exact proportions.  From there, I laid the artwork down on top of my panel and used an exacto-knife to cut button holes.
BTW, if you're doing large format printing, GET SAMPLES before you print!  I tried Kinko's thinking they'd have good quality prints, but when I saw the sample I was literally counting ink dots at arm's length.  They had 6-year-old large format color printing technology.  I went to a local place called Dean's Blueprinting and got it done on a brand new 1440 DPI spool printer, on better paper, for the same price.
Oh yeah and when you print, leave a border around your actual artwork that matches your case color...  or continue the artwork pattern...  cuz I thought I had the dimensions exactly right, but now have a little tiny band of white showing on one side.