Well, Race Technologies got a call!
p/n left xb1.e7.23 and right xb1.e7.24.
Out of the Brembo catalog these have an msrp of $850 each. These are racing, or more correctly TRACK DAY, calipers as the cost savings are in the production of 2-piece castings vs 1-piece forges or billets and Fe inserts instead of Ti. For reference, the cheaper of the two F3 4 piston calipers msrp at around $950. The biggest downside is the lack of any bridging which will reduce the calipers torsional stiffness vs with a bridge. The question is it enough to have any performance impact; The AP kits by Essex only have a single bar bridge.
Info is top of pg 24 in this doc:
http://www.brembo.com/it/Auto/Racing...MBO_RACING.pdf