Twin pot calipers + larger rotors for the rears, series 1 AU??

[SVT8]

Iv got a brake kit for the front already on the car with twin pot calipers and ba/bf 328mm rotors, i wanted to know if the rears could be upgraded as well?.

Are there any larger rotors and possibly twin pot calipers (from au II up to fg) for the rears that fit an au series 1 diff?.