On the control panel I order a 36"x 18" x 1/8 thickness and after I drill the holes for the buttons I sandwich the Plexiglas down by using a few buttons to hold it in place and also a couple of clamps as well. For the marquee as far as the length goes, it just depends on the size cab you're going with. Thickness though I go with 1/4 inch for the back side and 1/8 inch for the front. I get my Plexiglas from estreet plastics. Great prices, and they have alot of colors to chose from. You should check them out online. Hope this helps, and good luck with the build!