I've got an EJ20T from a 2005 Saabaru (9-2x) and a burned long block from a 2004 Forester 2.5XT that I've been thinking of doing this to. Probably leave it as a slushbox for now tho.
Wish there was a way to retain the AVCS without having to source an STi or Forester ECU/harness. . . or go open source.