Quadratec has the best prices. Just get some cheap ones as you will tear them off of you get serious off roading.
Does it have the frame tie below the engine (part of the HD suspension option)? It will keep the frame from flexing and shearing off the oil filter housing . Not needed for a mallcrawler, but those tires and the lift looks like a soon to be mudpuppy.
eta: they make some bars that bolt onto the frame as side protection, they also work as steps.