This thread is a great resource that I wish I'd had when I did mine a couple of years ago. I'm still happy with the setup I landed on though. Cam Motion Stage 2 truck cam (3-bolt), Chevrolet Performance LS7 lifters with BTR beehive springs and moly pushrods. Just finished a 2500 mile camping trip through the northeast pulling our 7500 lb camper, and never ran short on power anywhere. On a few long grades when I had to downshift to 3rd, I had to keep my foot out of it or it'd keep accelerating.
Side note: I have never been able to find a chart or performance data for VVT vs non-VVT at lower RPMs where it's supposed to be most effective, so I'm still skeptical of its benefits outside of fuel mileage. I also have a 2007 XL Denali that still has the stock cam and VVT and the 2012 with the 3-bolt cam will outrun it off the line pulling the same camper, all the way through the rev range. On the same highway entrance ramp near my house, I'm 10 mph faster merging onto the highway with the 2012 than I am with the 2007 when towing. The only significant difference is the cam. And both are Black Bear tuned for premium fuel.