What brakes work with ATS spindles

[Stroha1]

After searching for brakes for ATS Spindles I am confused. They are supposed to be compatible with c6 brakes. If you search Wilwood for a ATS spindles 7 kits come up. If you search C6 kits other options come up. What’s the difference?

[130fe]

The base C5/C6 are the same caliper (dimensions), just made differently (cast vs ?, I forget which one is which). You can use any C5/6 variant, OEM or compatible Wilwood kit.