Rock auto doesnt even show a listing for rotors or pads for the front of the car. They have Calipers though. For the price they want I’d rather rebuild mine, they aren’t hard to do.
When I discovered RockAuto 20-some years ago, it was a "one stop" place to get into catalogs for so many brands of parts they carried/had access to. So I used that website for such, then as now. The issue is that they, like any auto supply chain, will change their vendor listings every so often, bringing in new lines as others are removed. To me, what's on that website can be a good gauge of "what's out there", which a local auto supply might have access to if they might desire to check. So, RA has LOTS of stuff/listings which the locals and chains might not have access to, but RA does NOT have everything for everything, either.
The issue with the referenced Corvette calipers was that moisture in the brake fluid would cause corrosion in the caliper piston bores, resulting in leaks. The caliper halves were quite expensive, back then, which is where the stainless steel sleeve upgrades came from. Which might also be performed on the Budd calipers, too?
When the "box stores" can't provide what you might need, then you have to seek out speciality vendors, as mobileparts. OR you can go there FIRST and skip all of the frustrations of dealing with counterpersons who only can find what's in the computer's databvase, with all due respect. The speciality vendors will become MORE important as the vehicles needing their parts age-out of the auto supply databases.
To me, the amusing thing about the factory disc brake systems is that the original multi-piston calipers (Budd) were replaced with the single-piston caliper (which was highly-lauded at the time), but by the later 1990s, ALL super-perf vehicles had multi-piston calipers again, some up to 8 pistons per caliper. A more even application of the brake pads, they claimed, for better breake performance.
Enjoy!
CBODY67