I have seen the FC caliper fronts (any links on adapters and possibly mini cooper rotor options and part numbers?)
What about rear? Possible dual rear calipers?
Any info works... thanks.

The AJPS RX7 caliper bracket uses smaller Civic EG rotors.
AJPS also makes an adapter bracket that uses larger S13 rotors for the rear and you can reuse the AE86 rear caliper.

I bought my RX7 off a member here a couple years ago and it uses Mini Cooper S rotors but I forgot his name.
I run DBA4000 rotors, part# 4542SL and 4542SR.

Technotoytuning is supposed to making an adapter bracket which should allow you to run dual calipers and use various calipers (S13, Z32, AE86, wilwood, etc.).
Not sure about availability.