What is it you're exactly looking for from your truck? First thing I would do before doing an intake or exhaust is getting a set of gauges. Pyro (EGT), boost, and tranny temps. This way you will have an idea of what the normal driving #s will be. Typically when you add an intake and exhaust your EGTs go down and your boost may rise slightly. Gauges are not a necessity unless you really start to mod your truck, but should something start to act differently on your truck while driving your gauges would be nice to have some #s to work with.
Here would be my suggestions what to do safely to your truck.
2. 4" turbo-back exhaust
3. Intake but stay away from the K&N drop in filter.
Depending on how well your truck was maintained would determine how far in aftermarket upgrades I would do. I'm not sure how mechanically inclined you are, but I would check all your fluids and see how dirty they look. This might give you an idea of how well the vehicle was taken care of if you don't have any service records to go by.
Sorry for all the rambling...by the way,