[Tom Line]

Laminating 1/8 won't increase the stiffness that much.

You want the skins on a lamination as far apart as possible to increase rigidity. If you're going to laminate, better to buy the 1 inch thick insulation styrofoam (blue or pink). Cut out (cheese hole) the styrofoam.

Lay your glass on an old doorwall window (get it for free off craigslist or the garbage) in whatever size you need, then use epoxy to glue it to the top and bottom of your lightened styrofoam.

You'll get essentially a honeycombed panel for far less cost.