I've already done this for you...
http://www.subaru-svx.net/forum/show...6&postcount=39
The attached file shows possible pre-made DBA discs...at least for a chance to match them.
Another member...can't think his name (maybe Needforspeed? Ron?) suggested the Australian Ford Territory rear discs might work...same PCD, right diameter and thickness apparently, but I never checked.
Matt