I'd advise against retrofitting brakes from other car. Of course, illeffects may matter less for not tracked car, that is not pushed and driven with nannies on, but it still feels wrong thing to do. OE twins brembos IIRC will cost 2.5K for brake part + cost of wheels that will clear them (original IIRC didn't), or extended studs & spacers.
Still, can you tell what issues your brakes had that warrant caliper replacement? Usually most issues can be handled by simple rehaul of brakes. Replacing seals, regreasing, if worn, pad change, sometimes extra bedding, with calipers very rarely getting to state of not usable.