Watch out for catalytic converter and exhaust pipe heat. Another forum had a guy who made a 1/2" or 3/4" thick UHMWPE skid and it had a big brown hole that formed near the exhaust system. He made a one piece skid and melted/bent it to shape.
I agree 1/4" is probably too thin. Aluminum skids are usually make 1/4" thick. That may be adequate for the gas tank if you're mostly wanting to eliminate punctures. It certainly will be good padding on the aluminum diff case and T case, but it won't be very stiff.
2008 SE 4WD, Crew Cab, Long Bed; Leer 180 Cap, 2" Receiver hitch, Trailer wiring in bumper. Cooper 245/75/16 M&S (Winter). Cooper 265/75R16 ATP (Summer). Full set of Hefty skids, TJM Coilover w/HD spring, SPC upper control arms and 2" rear add a leaf plus 1" block. TJM extended travel rear shocks. Pyle backup camera wired to a Pioneer radio.