tough crowd 
Personally, I emphasized ranged defense. With Scorpion Shield, I got very nice s/l def as well without even building for it.
Which sets? For ranged def that means Blood Mandate, Red Fortune, Numina and Trap of the Hunter. I didn't slot Thunderstrike but that's good too. When to get it? Whenever you can. BM, RF and TotH can all be found at lower levels, it's certainly never too early.
Global = Hedgefund (or some derivation thereof)
What are the good sets to get for my thug/ff build, and when is it a good time to get them? What sets are the ones for extra def that you need?