I'm confused, you are asking for Hawk HP+, then are considering using stock GM pads? Huge difference.
My car is a C6 Z51 daily driver that sees 1/2 dozen HPDEs per year. For my needs, the stock Z51 pads are sufficient. They barely start to show fade at the end of track sessions under heavy braking, nothing dramatic. From what I read here, the C5Z06 and Hawk HP+ pads would work also for my needs.
if you have to call Friendly Chevrolet & Talk to JOE Tell him you are a friend of tammy that does the car shows down at Baydo chevrolet he may give you a deal.
Stock C5 Z06 pads will be better than Hawk HPS but just under the performance of HP+. Don't know if COA or CHP will have them in stock.
You could get them from Competition Specialities. Friendly Chevrolet, Bruce Titus Chevrolet or any of the larger Chevy dealers will have them but they will be pricey. Corvettes of Auburn would be a good choice. Dan may have the Hawks in stock or he could get them from Competition Specialties. He can certainly get the GM pads.
Most dealerships sell parts to area auto repair shops for 20% off GM retail if they have a parts contract, so the best you could expect over the counter is 10% off or maybe 15%.
Even Tire Rack charges $125 for the HP+ C5 front pads.