I play SR3 basically exclusively (although surfing on Drivethrurpg, I'm now considering going back to SR2

However, I have most of the books, and the ones I don't have I'll be able to pick up for about $40.
If I were to buy a book for SR3, that is not actually part of the SR3 line, what would you recommend?
I love SOTA style books, but I don't see any. Corp Enclaves and the Shadows of South America (or whatever it's called) both like tres cool. Street Samurai Catalog (from SR2) is also very cool and makes me miss SR2. Are there any other books which can translate easily to 3rd edition and are worth picking up?