Well, there's a few different ways of going about it. You could track down a stock skid plate, and that's adequate for light to moderate wheeling. There are many more heavy duty options from several companies in the aftermarket. Jcr, Dpg, and Dirtbound offer rail to rail coverage. Rustys, Warn, Skidrow, and other have ones that mount to the drivers side frame rail and trans crossmember. These are not quite as strong but adequate for heavier wheeling. And yes, you could make your own. Depending on your skill level and tools available you can pick your design. The mounting will be the tricky part as most of the metal in the area isn't thick enough to simply bolt to, and its a tube shape so you cant get to the inside to pace a washer and nut.