Honestly, considering the price of most OEM products, you may be better off going aftermarket. More protection, and probably not too much more expensive, if at all.
I can highly recommend GoRhino products. They make brush guards for the Titan/Armada. I've had my GoRhino winch mount guard on for almost a year and it's rock solid. They make multiple models.
Here's an example, their step bumper without headlight guards is under $300 shipped. Not a bad deal. -->
Go Rhino® - Nissan Titan LE / PRO-4X / SE 2010 3000 Series Grille Guards
I'm honestly unsure of how different this is from my winch mount guard. I paid just over $500 shipped for my guard. It may be a bit beefier, considering it's designed to handle a winch. Regardless of what you settle on, good luck!