They should be an option. If they aren't, you can always get your own. Since this is an aftermarket company, it will drive down the price of the option and the car to not offer this through GM. You may want to consider getting Brembos on your own and selling your existing brakes via eBay, Craigslist, or some other method.
PENSACOLA PEOPLE, PM to trade the following for my stock SS parts: VR Heritage Grille, used exhaust, used intake, ported throttlebody