To answer your question, YES. Airbags help rear suspension sag, additional trans cooling with a trans temp gauge is helpful, etc. However, most have found, and I count myself also, that even with all the upgrades, it still won't do the same job as a bigger truck.
Need many more specifics to give you a good answer though. What truck do you have now and what are you trying to tow with it? Where are you towing, local or through the rockies? If you haven't had the trailer loaded up and on the scale, then that is the first place to start. Find out exactly how much weight you are dealing with and what you got to tow it with, and we can go from there.