Looks like solid advice.Both are solid brands and produce nearly identical gains. If you trust one shop more to do the install and tune, that's how I'd chose. If that's a tie, go by price. Lots of internet retailers make prices competitive on the name brands. A car with headers and a proper tune are going to make same power from shop to shop if you are dealing with an experience C6 shop.
I'd actually toss LG in the mix too. LG's 1.75" design had a little more mid range gain than other brands. I run those (same model as used for the Z06). The 1.875" headers are all nearly identical due to space constraints. Pfadt recently introduced some new headers that look very nice. While they are known for suspension work which is top notch, I'd feel very comfortable buying their headers if they are competitively priced.