Lauren: Essex kits (sprint & endurance) are popular in US AP-racing race caliper front-only BBKs by known in field brake shop, that retain braking bias with rear stock brakes, and have common & thick brakepad shapes, letting to use wide pad selection & save a lot on wearables on top of usual BBK benefits (of thermal capacity/cooling/weight reduction). Race calipers though, so not that good for DD, at least where there is winter with roadsalt. And US based shop, thus less competitive offering on this side of pond.