The great upgrade I went with was getting 07 Tahoe rotors, calipers and, brackets. They'll bolt right up and it's an upsize of an inch of diameter. I got stoptech rotors and pads, the "one click brake upgrade" on amazon (for an 07 fronts only). Then I went to the local parts store and got the calipers and brackets (front only). The rears didn't change. I got Russell stainless lines. The 07 tahoe fronts were also the same as the 05-06 and some previous silverado if it had the single piston rear calipers. If they were dual piston the fronts were the same size. You can also get this stuff from a junkyard but I wanted new stuff and I got the slotted and drilled for mine all the way around.
I saw that if you order from stoptech directly, since they don't have these particular kits on amazon anymore, you can get the "heavy duty truck kits" I guess they are better for stopping if you tow a lot. I'd go for that if you're going to have all that rotational mass to stop. btw if you upsize the front rotors and calipers like I did, 16's will no longer fit if you had to use your spare in an emergency. My 17 inch z71 wheels barely clear but they did so without issue.