I dont have a pic to share (but if you check my gallary, you'll see I DO off-road in my Expy), but I'm sure you can order the plates separately from the parts counter.
The skids are NOT like what you'd find on a Jeep or some other off-road capable vehicle. My EL has the factory skids and the gas tank skid is made of plastic... and the others are very thin (1/16" steel t-case skid, 1/16" aluminum [looks like, anyway] front suspension skid).
I asked my Ford dealer if a steel gas tank skid was available and there isnt (at least not as of January).
I know they can do some pretty amazing things with metallurgy and design, but these just seem completely under-engineered for this size of a vehicle, IMO.