I there is a thread over at another great Cobalt site called SSCOBALTS dot NET with a topic of suspension 101.
There they list all of the GM part numbers for all of the cobalt suspensions parts.
Checking there and here with the folks that have done it many times, I chose MEVOTECH CMS50174 & MEVOTECH CMS50173.
These are forged Aluminum control arms and coupled quite well with the FE5 struts, stabilizer end links, and FE5 sway bar for my 08 LS
Now as I recall, and i could be wrong, but I thought 05 FE3 control arms were stamped steel. Again, I could be wrong.