I have a 2006 1500 z71 2wd with the tow package. Just bought a 26 foot camper weighs 4300 lbs. Looking for recommendations to help improve towing. I have no desire to be going down the road with a travel trailer doing 80 mph, If I can run 60 to 65 comfortably I will be happy.

 

bumper pull or fifth wheel

nothing you can add will raise the tow rating but you can definitely improve it.
-adjustable rear air bags
-weight distribution hitch with sway bar if bumper pull is a must have

 

Things I've done on my tow vehicles...not so much to improve performance, but to improve reliability/control/longevity of components:

Upgraded shocks to Bilstein 4600s- the blue/yellow shocks. Made a HUGE difference in control and ride, and eliminated bouncing/porpoising.
Upgraded to Royal Purple Max ATF trans fluid - or in your case, you could just upgrade to any brand Dex 6.
Upgraded to an HD cluster - added the trans temp gauge, plug 'n play, no additional wiring needed
Installed a rear diff cover with cooling fins. The rear axle is the weak link in your powertrain, and it'll get hot on long drives
Changed axle fluid frequently - 75W90 full synthetic

 

Blistien shocks , I don't have a transmission cooler as I don't need one with a 1500 suburban pulling (dry) a 3200 trailer. No problems. If you are pulling it across high terrain (mountains) might look at the GVW of the trailer even at the manufactuers minimum at 10-15% higher because of hill's mountains ect.