Most people make their own out of Starboard (Available at Home Depot) Get a piece of cardboard and cut it to the size and shape you want, then sketch where you want the various instruments to be. Once you have finalized it use the cardboard as a template and make it out of the Starboard.
Grainger carries a product that is perfect for the job, it's Black in color ,1/4 inch thick with a very nice texture. I did my v in it years ago . And the sheet was 30.00 (36x24) if memory serves. And it looks great with white or black gauges. I used black..