Redline Performance in Arizona - Some guys on the board got theirs installed there, and they say to call them whenever this question comes up, however, not sure that there is a "kit"
www.carmodifications.com - the Nam in Minnam. Offers a twin turbo kit that somebody was supposed to be the first install for early this summer - no word on whether this actually exists. I lined up to order and be the guinea pig, but they were too expensive for me.
http://www.technikmotorwerks.com - The other half of Minnam - a new name, there are those who say you can still get what was the old Minnam kit from them, but I don't recall seeing anyone post who actually got one.
www.imprezars.com - Larry Ganz - the king of customer service in this business. He sells an N1 turbo kit he says is sourced from the same suppliers that JCSports uses.
UPRD - said they were looking to do a kit.
I think FAT and redline have their descriptions reveresed above. Redline is in Florida not AZ. Forced Air Tech is in AZ and has done at least 25 local Subaru turbos plus he sells many kits online as well. Quite a few people are running the various stages available from FAT.