Catch can
 

Are these a good idea for 4th gen LS engines or just something for newer Camaros.

All internal combustion 4 stroke engines benefit. You don't ever want oil ingetion in the intake air charge.

Just make sure you route it correctly through the PCV system, otherwise all that oil can feed right into the intake and overpressureize the crank case. If you're lucky in a case like that you'll just be burning off excess oil for a year from all reaches of your exhaust. :/

I'd save up and do the following BEFORE a catch can:

LS6 intake
LS6 valley cover
LS6 PCV system

THEN do the can.. and mount it to the left cylinder head (looking towards the back of the car), not the body. Once the PCV system is altered the can can go directly in it's place.

Get the can from WS6 store and then do the LS6 conversion if you really want it. While the LS6 setup is better and it's what I have on my car, it still allows oil to pass through. The catch can is the best solution.