Mechanical Disc Callipers - BB7 Road ideally. Flat mount.

Get BB5 and flat mount to post mount instead.

This.

I bought some cheap bb7 from aliexpress for my mtb and was underwhelmed (I have bb7 on a couple other bikes and really like them). Swapped to some old beat up bb5 from ebay and braking is so much better.

Suspect the bb7 were seconds (I stripped them down and found 2 washers where there should be one in one of them but even after rebuild they weren't great) or just downright fakes.