First off, subaru uses a 5x100 lug pattern, so stop looking at them.
Second, I'm having trouble understanding what you're asking exactly...if you just want a larger rotor to use with your z brakes, there are a multitude of kits available.
Here's a couple:
http://store.yahoo.com/ginnmot....htmlh ... brakes.php
Also, a company in the UK called Apex Performance makes a kit.
If you'd rather do it on your own, check out this guys page:
http://www.ashleypowers.com/Im...x.htmHe's got the specs for the adapter plates, but the pic seems to be missing. I'm sure you can email him about which rotor he used and what the plate specs are.
EDit: He used cobra rotors and hubcentric rings.