The seats will fit, but will sit an inch or more lower than your stock Forester seats. So be ready for that. You may want to switch bases or rails or something to make them fit better. I wanted to fit STI seats in my car but turns out that Forester and Impreza seats sit a good bit taller.
The dash won't fit. I think the BH (Outback platform) is a bit wider inside than the SF. You can grab any engine parts, wheels, brakes, etc... are all the same (on the H4 engine, NOT the H6) or will fit, but the interior is a different setup entirely (except for the CD/radio... lol).
Any more questions, just ask. I have the Outback and a SG Forester in the family, so I can compare between the two.