Hmm.
Maybe it would be worth considering the RX7 4-piston calipers. I'm fairly sure from my brief googling that the FC turbo has 4 piston calipers designed to go with 276mm rotors. They're 165mm centre to centre, so you'd need some kind of dog bone adapter.
http://evo123.net/fo...2-brake-upgrade
Some basic info but this guy seems to have had a similar idea to you
http://www.dsmtuners...alipers.360222/
Not entirely sure on which rotors will suit, but if it was me doing I'd likely try to use stock rotors and have the adapters made to suit these. Although possibly the stock rotors are too thick for the Rx7 calipers.
Edited by doommachine, 27 December 2017 - 11:11 AM.