Dude
Why not run nissan S13 SR20 calipers and rotors.
Im currently doing a 4AGTE conversion on my AE86 and going to use S13 SR20 calipers and rotors. For around $250 for a full second hand set you will be laughing.
Why go for the JDM 86 Disks all round when you can upgrade to a bigger brake for the same price and same amount of effort.