I'm not sure what your plans are for this car, but you may find that the 324/30mm Brembo/E31 840(C)i front calipers/rotors are a more affordable solution. They're a Forged, two piece caliper with Four pistons and offer a pretty wide brake pad selection.
Along with this, they're direct fit...No fooling with fabbing adapters/etc. Not a massive, extreme BBK...But, would certainly be an improvement over stock, and IMO, probably would still be a good match with the original brakes out back.