You're looking in the wrong places
, people OC AMD's just as much especially in these forums.
I have a 35w 2400+ XP-M OC'd from 1.8GHz to 2.5GHz currently, it'll run 2.7GHz but it requires more Vcore than I care to put in it.
The 3500+ 64's winchester chips (they have the .9u technology) can OC better than the 3500+ 64 newcastles.
Best place to start is read the 'Basics on overclocking' sticky at the top.
Also the 3400+ 64 socket 754 mobiles are supposed to be some good OC'ers also.
Both the mobile and the 3500+ I've listed off I've seen get to 2.7GHz on air through reviews I've read and user posts.