FYI, I have z32 Rear Brakes and have also done tons of research on 15" rims since I want some track specific rears. From what I have gathered you will need spacers for most 15" setup in the rear with Z32 brakes except for RaceStar Industry Wheels.
Race Star Industries - 2012 Catalog
So if your looking for something like that I know they will fit but for everything else I have searched...a small spacer is required.
If your looking for the front, I personally am running 30mm Z32 front calipers with Z33 Track rotors. But then again I wasnt planning on running 15" up front.
Are you looking to run 15" all the way around? If your question relates to a Drag Racing Setup (which is what I am hoping) then the Drag Zilvia thread has great info.