Look at the other skid plates in the thread I posted. The engine skid covers the oil pan, and it continues back to cover the transmission, and reaches the crossmember. At the crossmember the transfercase skid plate starts, which will go quite a ways back. There is one company, Appalachian Armor, working on a full width tcase skid plate that fits over the catalytic convertor. At that point you're close to the rear axle, and it's just a matter of extending with plastic.
Oil pan skid
