2010 sti ? Will most likely kill all the cars you mentioned, leather, navigation and imo the sedan looks beautiful.
My mate just bought a golf R, honestly it's a really nice car, however at the end it's just a golf.
Then there's there 135i and 335i personally would go for a 335i.
I'm also in the same boat, getting rid of my M3, still don't know what to go for :/