Realize that the bull bar is for asthetics only-- it is fake and will not take a hit better, nor can you winch from it, so drive accordingly. If you are going to do any off-roading or trail riding, you need the following:
Front tow hooks,
Rear reciever with shackle or rear tow hook,
Skid Plates (front engine, transmission, transfer case and fuel tank).
Rock rails. (if you are not going to lift it these will save your rocker panels from carnage. If you are going to lift it, these will still save your rocker panels from carnage).
Of course, you must also realize that you will eventually lift it anyway, resistance is futile.
All of the skids and tow hooks are available from Mopar. The mopar versions are generally less expensive than the aftermarket, but they are only light duty. The Mopar tow hooks are fine, however.
The exhaust is the best performance mod for the buck from what I hear-- the stock exhaust is necked down. The intake... well that depends on what you put on it and is highly subjective. The stock intake is probably the best for off-road (unless you put a full snorkel on it). See 4x2 street performance section for more details.
The Mopar cargo organizer is a favorite. It will cover the rear cargo bay and organize items in it.