I was inspired by the woody in my build,  I am using a 4:3 21.4 inch screen, worked out pretty well bezel wise.  The problem with wise screens, htough, is the big top and bottom bezels.  To compensate, I would make the admin panel right below the screen a little larger, and bring the marquee down a few inches.  The marquee area is, what 6 inches high?  Make it 9 or nine, that will eat up a few more inches of bezel.  It will look weird with no bezel on the sides and 6 inch bezels on the top and bottom.
40 inches will be cramped.  I think my panel is 34 inches wide or something like that...