Chip Vs. Reprogrammer - Chev 350

I am looking to increase the performance of my tow rig. It is a '99 Chevy Tahoe with the 5.7L I have already purchased a conical K&N, removed the air filter casing cover and installed a magna flow muffler. I know nothing about chips and recently learned about some of the benefits of a reprogrammer. Is one better than the other and does anybody have some suggestions on what I can do to allow for a better tow of my XJ to the trail?

The Hypertech Power Programmer III is definitely the best way to go. HP/TQ gains are measureable and if you make any gearing/tire size changes, you can input those as well so they'll be automatically compensated.