I've got Harrop front brakes- callipers, discs, hats.  They are sensational.  Also expensive  (about $5000).
They fit under 89 17" standard rims.
They are Aust made, and harrop back their product.
I looked long and hard at US and Euro options, and reckoned the local product was cost effective.
If you have the skills /engineer to adapt Brembo or similar, that might be an option.