I'm working on this myself, I wouldn't use that power stop kit. I'd upgrade to GMT900 front brakes and dual piston GMT800 on rear if you don't already have that. That GMT900 brakes will require you have 17" rims though. If you have the 17" rims they're are direct bolt on. You can get the power stop kit for GMT900 fronts with those brakes but MUST be from a 2010 or NEWER NNBS / GMT900. I'd do 2011 or newer to be safe (to 2014? not sure of last year of NNBS). If you don't have the dual piston caliper in rear end, then swap it out with the GMT800 dual piston caliper setup.
Next replace your flex lines with lines rated for hydro boost and swap out your fluid. I'm currently going to swap with steal braided hoses.
HERE is my post.
If you go with the next brake design you'll end up having to cut the calipers and shim them and or newer wheels. I MUCH prefer things to be a direct fit, otherwise you'll run into complexity issues if you take up the shimming, okay fit philosophy. Imagine wife taking to shop for instance and they loose washers (shims) during a brake job. Just my 2 cents... simpler is better.
FYI ~ I use the HECK out of my 2001 Z71 Tahoe. It stops GREAT but I take immaculate care of the mechanicals. I can lock up the wheels with the stock braking system. My plan is to put the GMT900's on the front tough when I find a set at the junkyard.